COLMI P78 Smart Watch Review: Rugged AMOLED for Outdoor Enthusiasts

The COLMI P78 Smart Watch targets a specific buyer: the outdoor enthusiast who refuses to choose between display quality and durability. Most budget smartwatches with AMOLED displays have a polished, urban aesthetic that feels out of place on a muddy trail or in a wet forest. Most rugged-looking budget watches sacrifice display quality for toughness. The P78 attempts — and largely succeeds — at delivering both: a genuine AMOLED display in a robust, outdoor-ready build that suits active use in demanding environments.

In this full review we cover the P78's design and ruggedness, AMOLED display performance outdoors, health and sports tracking, battery life, and how it compares to its natural COLMI rivals — particularly the P73 (rugged but IPS), P76 (AMOLED but water-focused), and P82 (AMOLED with GPS).

Design: Where Outdoor Capability Meets AMOLED Quality

The P78's design communicates outdoor capability without resorting to the aggressive camouflage styling of the P73. The case has a purposeful, robust appearance with protective elements around the display edges and a build quality that feels genuinely solid in hand — not the slight plasticity of the most entry-level budget watches, but a substantive, confidence-inspiring construction.

Side buttons are large enough to press confidently while wearing gloves — a practical design detail that matters for cold-weather outdoor use. The silicone strap is robust and textured for secure grip during dynamic activities. The strap's attachment mechanism feels secure and unlikely to accidentally release during high-activity use.

Available in multiple colour options that lean towards outdoor-appropriate palettes — deep colours, natural tones, and subtle styling that doesn't look out of place in a woodland or on a mountain trail. The P78 doesn't demand attention in the way the P73 does; it has a quiet confidence that suggests serious capability without needing to shout about it.

IP68 water resistance is standard across the P78, providing protection against rain, sweat, river crossings of moderate depth, and general outdoor moisture exposure. The rating is appropriate for the hiking, running, and cycling activities the P78 targets. For swimming specifically, the P76 with its 3ATM rating is the more appropriate choice.

The overall impression is of a watch designed by someone who has actually used a watch outdoors rather than someone who has tried to make an outdoor-looking watch at a desk. The practical details — button size, strap robustness, case protection around the display edges — all reflect real-world active use considerations.

The AMOLED Display: Why It Matters Outdoors

The P78's AMOLED display is the feature that most clearly differentiates it from the P73 and other rugged-aesthetic budget watches. AMOLED technology has specific advantages that are particularly relevant for outdoor use:

Sunlight Readability

AMOLED displays achieve high peak brightness levels that compete effectively with ambient sunlight. More importantly, the true blacks of AMOLED mean that dark display elements don't reflect sunlight back into your eyes the way backlit IPS panels do — dark watch faces on AMOLED actually absorb some ambient light rather than reflecting it, which improves contrast in bright outdoor conditions. When running or hiking in direct sunlight and glancing at pace and heart rate data, the P78's AMOLED display is noticeably more readable than IPS alternatives at equivalent brightness settings.

Visual Quality for Data Displays

During exercise, your watch needs to present pace, heart rate, distance, and elapsed time in a format you can read at a glance without breaking stride or stopping. The P78's AMOLED display delivers crisp, high-contrast data that's immediately legible in a quick wrist glance. The visual quality that makes AMOLED watches look good at a desk also makes workout data easier to read on the trail.

Battery Efficiency With Dark Watch Faces

For outdoor use where charging access may be limited, AMOLED's efficiency advantage over IPS is relevant. A dark-background watch face on AMOLED consumes significantly less power than any IPS display, because black pixels on AMOLED consume zero power. Choosing a dark watch face on the P78 actively extends battery life, which is a practical benefit for multi-day outdoor trips.

Health and Fitness Monitoring

Continuous Heart Rate Monitoring

24/7 optical heart rate monitoring provides resting and active heart rate data throughout the day. During outdoor activities — hiking, trail running, mountain biking — real-time heart rate display on the AMOLED screen allows zone-based effort monitoring without stopping. High and low heart rate alerts are configurable, and the heart rate trend data stored in Da Fit provides post-activity analysis of how your cardiovascular effort varied throughout a session.

Blood Oxygen (SpO2) Monitoring

On-demand SpO2 monitoring is particularly relevant for outdoor enthusiasts who train or travel at altitude. As elevation increases, atmospheric oxygen pressure decreases, and blood oxygen saturation drops in response. Monitoring SpO2 during ascent — a reading between sets of a hill climb or at a mountain campsite — provides useful acclimatisation data. Values consistently below 90% at altitude indicate inadequate acclimatisation and warrant slower ascent or rest at the current elevation.

Sleep Stage Tracking

Automatic overnight sleep tracking provides light, deep, and REM stage analysis alongside a morning sleep quality score. For athletes who train heavily outdoors, sleep is the primary recovery tool, and monitoring sleep quality alongside training load gives context to how well you're recovering from demanding sessions. The P78's comfortable design makes overnight wearing practical even during camping trips or multi-day outdoor events.

Stress and HRV Monitoring

HRV-based stress monitoring provides morning recovery status data. For outdoor athletes in periods of heavy training — race preparation, multi-day hiking challenges, or adventure racing — monitoring morning HRV scores before deciding on the day's training intensity is a practical overtraining prevention tool. A low stress score (high HRV) indicates readiness for a demanding day; a high score suggests rest or lighter activity is wiser.

100+ Sports Modes

The P78 supports over 100 sports modes covering the full range of outdoor and indoor activities. Hiking, trail running, cycling, mountain biking, rock climbing, swimming (within IP68 limits), skiing, snowboarding, kayaking, and many more are included. The breadth of sports mode coverage ensures the P78 can track virtually any outdoor activity regardless of how varied your pursuits are.

GPS tracking is phone-connected rather than built-in. For the majority of outdoor activities where you're likely to carry your phone in a pocket, pack, or jersey pocket, phone-connected GPS via the Da Fit app provides accurate route tracking without the battery cost of built-in GPS hardware. For truly phone-free outdoor tracking, the COLMI P82 or V75 GPS are the appropriate choices.

Step Counting and Daily Activity

Daily step counting, calorie estimation, and active distance tracking run automatically. For outdoor enthusiasts, daily step counts during hiking days can reach 25,000 to 40,000 steps — the P78 handles these high-activity days without issues, and the Da Fit app charts make it easy to see the contrast between active outdoor days and sedentary recovery days in your weekly summary.

Technical Specifications

Display: AMOLED touchscreen
Bluetooth: 5.3
Water resistance: IP68
Sports modes: 100+
Sensors: Optical HR, SpO2, accelerometer, gyroscope
GPS: Phone-connected
Strap: Robust silicone, interchangeable 20mm
Compatibility: iOS and Android
Companion app: Da Fit (free, no subscription)

Battery Life

The P78 delivers approximately 10 to 14 days of typical battery life under standard conditions — health monitoring active, notifications enabled, always-on display disabled. This is excellent battery performance that covers extended outdoor trips without daily charging.

For multi-day hiking or camping trips where charging access is limited, a fully charged P78 comfortably covers a week-long adventure. Using a dark watch face (which saves battery on AMOLED displays) and disabling always-on display can push battery life toward the 14-day upper end, providing additional buffer for extended remote excursions.

When GPS is used via phone connection during outdoor activities, the phone bears the GPS battery cost rather than the watch, which means the watch's battery is not significantly impacted by GPS-connected outdoor tracking sessions. This is an underappreciated advantage of phone-connected GPS over built-in GPS for users who are comfortable carrying their phone during outdoor activities.

Smart Features

The P78 connects via Bluetooth 5.3 and supports all core smart notification features: call alerts with caller ID, SMS and app notifications, music control, weather display, find my phone, alarm with vibration, and remote camera shutter. Bluetooth calling is not supported — for that, the COLMI P71 or P82 are the relevant models.

P78 vs P73: AMOLED Outdoor vs IPS Rugged

The P73 and P78 both target outdoor-oriented buyers but with different priorities. The P73 leads with a bold camouflage aesthetic that's immediately visually distinctive, paired with an IPS display. The P78 leads with AMOLED display quality in a more understated outdoor design.

If the bold visual statement of the P73's camouflage aesthetic appeals to you more than display quality, choose the P73. If you want the best outdoor-suitable display quality in the COLMI range at a similar price, choose the P78. The health tracking features are essentially identical between the two models; the differentiation is entirely design philosophy and display technology.

P78 vs P82: Outdoor Style vs GPS

The P82 at a slightly higher price brings built-in GPS, an even larger 2.13-inch AMOLED display, and Bluetooth calling. The P78 offers outdoor-focused design and similar AMOLED quality without GPS. The decision point is clear: if standalone GPS for phone-free outdoor tracking is a priority, the P82 is the better choice despite its less outdoor-specific aesthetic. If outdoor design language matters as much as health tracking capability, and phone-connected GPS is adequate for your needs, the P78 is the more compelling option.

P78 vs V75 GPS: Both Outdoor, Different Features

The V75 GPS (£58) is the purpose-built outdoor GPS watch in the COLMI lineup, featuring built-in GPS in a rugged design. The P78 offers AMOLED quality without GPS at a lower price. For hikers and runners who specifically want phone-free GPS route tracking, the V75 is the better choice. For those who are satisfied with phone-connected GPS and want to save money while getting AMOLED display quality in an outdoor-capable design, the P78 makes sense.

Who Should Buy the COLMI P78?

Outdoor enthusiasts who want a durable smartwatch with premium AMOLED display quality
Hikers, trail runners, and cyclists who want good display readability in bright outdoor conditions
Active users who want comprehensive sports tracking in a robust, outdoor-appropriate design
Those who carry their phone during outdoor activities and don't need standalone GPS
Buyers who find the P73's camouflage aesthetic too bold but still want an outdoor-oriented watch
Outdoor enthusiasts who want 10 to 14 days of battery life for extended remote trips

Who Should Choose a Different COLMI Watch?

If standalone GPS for phone-free tracking is essential — choose the P82 or V75
If bold camouflage styling is what you want — choose the P73
If swimming is a primary activity — choose the P76 (3ATM waterproofing)
If professional elegance alongside outdoor capability is needed — choose the P80 with steel strap
If GPS plus the largest possible display matters most — choose the P82 (2.13-inch AMOLED + GPS)

Verdict

The COLMI P78 successfully delivers on its core promise: AMOLED display quality in an outdoor-capable, durable design at an accessible price. For outdoor enthusiasts who want better display readability in sunlight, genuine durability for active use, and comprehensive health and sports tracking without paying premium outdoor watch prices, the P78 is an excellent choice. It fills a genuine gap between the purely sporty P73 and the GPS-equipped P82, serving users who want outdoor aesthetic and display quality without the GPS premium.

Rating: 4.3 / 5 — The best AMOLED outdoor smartwatch in the COLMI lineup under £45. Excellent display quality, purposeful outdoor design, and long battery life make it a strong choice for active outdoor lifestyles.