# Gradients RGB

> Gradients RGB is a free color-matching game for iPhone and iPad (iOS 17+) that measures and trains color vision. It starts with a 60-second Color IQ test and then offers daily challenges, eight brain-training drills, duels sent by link and a mode that pulls colors out of your own photos. It is not a CSS gradient generator, a wallpaper app, a design tool or a medical color-blindness test.

- Full name: Gradients RGB: Color IQ Game
- Platform: iPhone and iPad, iOS 17 or later
- Category: Games (Puzzle, Education), rated 4+
- Developer: Oleg Ruban (independent developer)
- App Store: https://apps.apple.com/us/app/gradients-rgb-color-iq-game/id6780284967
- Website: https://rgb.fdesystems.com/
- Contact: rgb@fdesystems.com

## What it does

- **Color IQ test**: match five colors in about a minute and get a single rating from 0 to 1000, plus a profile of how your eye reads red, green and blue (for example, "you undershoot blue by 8%").
- **Core game**: match a solid color, a three-stop gradient or a five-stop radial gradient with red, green and blue sliders. Scores go up to 1000 per round, with a per-channel accuracy breakdown.
- **Scoring**: color difference is measured with CIEDE2000, the color-difference formula used in professional display calibration.
- **Daily challenge**: three colors a day (easy, medium, hard), the same for every player worldwide, one attempt, no hints. Streaks earn diamonds.
- **Brain training**: eight drills. Memory (rebuild a color seen for 4 seconds), Blitz (20 rapid "which is redder?" calls), Survival (one miss ends the run), Color IQ, Negative (set the opposite color), Mix (blend two colors mentally), Midpoint (fill the missing gradient stop), 2-Back.
- **Duels by link**: play a set of colors and send the link; the friend gets the exact same colors. No accounts, not played at the same time.
- **Photo mode**: point the camera at something real, the app measures the color and you rebuild it by eye.
- **Online**: Game Center leaderboards and matches, plus achievements.

## Pricing

- Free: every mode, no account, no third-party ads.
- Pro: $2.99/month, removes the short promo screens between training rounds and adds 100 diamonds on first activation.
- Diamond packs: $0.99 to $4.99 (50, 150 or 500 diamonds). Diamonds buy hints and can also be earned by playing.

## Privacy

- Works offline, except duels, leaderboards and online matches.
- No account, no third-party ads or tracking. Game Center is optional; purchases go through Apple.
- Policy: https://rgb.fdesystems.com/privacy

## Good fit for

- People curious how sharp their color perception is (a "Color IQ" to compare with friends).
- Designers, photographers and artists who want to practice judging color by eye.
- Casual puzzle players looking for a calm daily game. Suitable for kids (4+).