Huetween
Guess the color exactly halfway between these two. 3 tries.
About Huetween — find the color in the middle
Huetween trains interpolation — judging the color that sits exactly halfway between two others. Finding a true midpoint is deceptively hard because perceived lightness does not move in even steps with the numbers, so your eye has to feel the balance point rather than calculate it. Designers lean on this when building smooth gradients, choosing an in-between tint for a palette, or blending two photos so the seam disappears.
You see two colors and get three tries to pick the shade that falls precisely between them. After each attempt the game shows how close you landed, tuning your sense of the middle.
This is the perception of intervals and midpoints in color space. Read about color midpoints and interval perception, or browse the full Learn about color library.
What Huetween trains
Huetween works your color interpolation: placing the shade that sits exactly halfway between two others. That is a different skill from matching. Matching asks whether two colors agree; interpolation asks you to invent a third color neither swatch shows you, balanced across hue, saturation and lightness at once. The true answer is the midpoint of the two in RGB, read back as hue, saturation and lightness, and rarely the number you would reach by averaging the two hues in your head.
How to play
Two swatches, A and B, sit either side of an empty dashed square. Move the Hue (0–360°), Saturation (0–100%) and Lightness (0–100%) sliders until the square shows what you think is the midpoint, then press Lock in guess. You get three tries. After each one, three per-channel hints appear: hue reads warmer or cooler, saturation and lightness read more or less, and a channel that is already close enough turns into a tick, which means within 8° on hue and within 5 points on saturation and lightness. Everyone gets the same pair that day, and every control is keyboard-reachable.
How scoring works
Each guess is scored as a closeness percentage, computed from the perceptual distance between your color and the true midpoint in Lab space rather than from raw slider numbers. Two guesses equally wrong in slider units can therefore score very differently, because the eye is far more sensitive to some regions of color space than others. Your result is your best guess of the three, not your last. The round can end early: at 97% or better, or when all three hints show a tick. You then see the true midpoint beside your best attempt.
What your score means
Read the closeness figure as a band, not a verdict:
| Outcome | Rough interpretation |
|---|---|
| 97% or better | Spot on; you found the midpoint, not just the neighbourhood |
| 85–96% | Solid; the day counts towards your streak from 85% up |
| Below 85% | One channel is probably carrying most of the error |
One day is noisy. The honest signal is whether your typical best creeps upward across weeks.
Common mistakes
The commonest error is averaging the hue numbers. Because the target is the RGB midpoint, two distant hues do not meet at the hue halfway between them, and the answer often sits at a much lower saturation than either end. A second trap is spending all three tries on hue, so the other two hints never improve. Third, players over-correct: a hint says more, they push the slider to the top, and the next hint says less. Halve the step instead. Finally, surroundings matter, because a bright room or a dimmed laptop shifts what you see.
Practice progression
(5 min, beginner) Read only the hue hint on try one, only saturation on try two, only lightness on try three; one channel at a time builds the habit of separating them. (10 min, intermediate) Before touching a slider, commit out loud to where the midpoint sits, then check how far off you were, which turns a search into a prediction. (weekly) Pair it with Huespan, which asks you to reproduce a lightness step rather than a midpoint, and read Color Midpoints.
The science behind it
There is no single midpoint between two colors: it depends on the space you interpolate in. Blending in RGB, in HSL, or in a perceptually uniform space gives three different answers, and only one will look halfway. Two things drive the gap. Display values are gamma-encoded, so equal numeric steps are not equal light steps; and perceived lightness itself rises non-linearly with luminance. See Hue, Saturation & Lightness and Delta-E and the just-noticeable limit for the model behind the score.
Limitations
Huetween is a game and an informal self-check, not a clinical or diagnostic tool. It runs on an uncalibrated screen in unknown lighting, so absolute scores are not comparable between devices. It measures one narrow skill, placing a midpoint on three sliders, and says nothing about color memory, harmony, taste, or color vision as a whole. A single day's result is mostly noise.
Where it shows up
Finding the color in between is quiet, constant work in a lot of trades. A designer building a gradient between a brand blue and a brand green needs the mid stops to look evenly spaced rather than bunched at one end; the numeric midpoint often looks muddy and has to be nudged by eye. A retoucher blending two exposures across a seam is choosing an in-between tone for every pixel of the transition, and any error shows up as a visible band. A painter mixing a third value between a highlight and a shadow does the same job with pigment, where the physical mixture almost never lands on the perceptual middle. Someone choosing paint for a hallway that joins a warm room and a cool one is hunting for the shade that reads as belonging to both, and picking a mid-tone for a chart series so the categories stay apart is the same work again. In every case the answer is on neither swatch in front of you: you have to construct it, then check it against how it looks rather than how it computes. That construct-and-check loop is what three tries of Huetween exercises.
Ready to find today's middle? Two colors, three tries, about a minute, and a fresh pair tomorrow.
Frequently asked questions
How many tries do I get?
Three in the daily puzzle. The round ends sooner if you reach 97% closeness or if all three hint channels show a tick.
Why isn't the answer the average of the two hue numbers?
The target is the midpoint of the two colors in RGB, converted back to hue, saturation and lightness. That conversion usually lands on a different hue, and often a noticeably lower saturation, than averaging the hues would suggest.
What do the hints after each guess mean?
Per-channel directions: hue shows warmer or cooler, saturation and lightness show more or less. A tick replaces the arrow once that channel is within tolerance.
Is my score the last guess or the best one?
The best of your three. A poor final try cannot pull down a good earlier one.
Can I practise without waiting for tomorrow?
Yes. The practice tab generates unlimited pairs, and lets you set the A–B distance and a difficulty tier that changes how many tries you get and whether hints appear at all.
Related reading & games
- Color midpoints and interval perception: why the halfway color is not the halfway number.
- Hue, saturation and lightness: the three axes the sliders move.
- Huespan (reproduce a lightness step) and Huekle (find a hidden color in five tries): related judgement games.
- Learn about color: the full guide library.
Understand it, now train it. The daily games stay free forever. A Personal Pass adds progress tracking (trends + export); Teacher / School tools let you assign it and follow a whole class. For teachers & self-learners →