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.