Color blind friendly mobile games: what to check before you install

About one man in twelve and one woman in two hundred have some form of color vision deficiency, most often trouble telling red from green. On a phone it matters more than on paper: small pieces, screens of uneven quality, bright light outdoors.

Many mobile games are built on telling colors apart, and treat color blind players as a settings toggle at best. Here is how to tell which games will work for you before you install them.

Which genres depend on color

Color sort and water sort. The whole puzzle is color. Without a second signal, it is unplayable for many players.
Match-three and bubble shooters. Most give each gem or bubble its own shape, which helps. Not all of them do.
Card games. Suits have always been told apart by shape, so solitaire works as long as the suit marks are large enough to read.
Block puzzles. Color is usually decoration, and the shapes and the grid are what matter. Generally fine.
Arrow and direction puzzles. Fine if the direction is drawn. A problem only if color alone shows it.
Nonograms, sudoku and minesweeper. Built on numbers and positions, so color is rarely essential.
Mahjong solitaire. Tiles are told apart by drawn symbols, so color matters little, but small tiles on a phone screen can be hard to read.

What good design does

Accessibility guidelines for games say the same thing in different words: never use color as the only way to show something. If color carries information, a shape, a pattern, a label or a position carries it too.

In practice that means:

Symbols on colored pieces, always on, not hidden in a menu.
Palettes chosen to stay distinct for the common types of color blindness, not only for typical vision.
States like selected, wrong or done shown by an outline, an icon or motion, not only by a change of color.
Text and numbers where they help, readable at phone size.

A color blind mode is good. Not needing one is better. A mode has to be found, and every player who needs it first has to suspect that the game will not work for them.

This is also easy to test. Free simulators show a screenshot as it looks with each common type of color blindness, and a developer who checks every screen with one finds most problems in an afternoon.

Color filters are a different thing

Some games offer filters that shift the whole palette for protanopia, deuteranopia or tritanopia. They can help, but they do not add information, they only move it. If two pieces still look alike after the filter, the game is still unplayable. Shapes do not have that problem.

Android also has system-wide color correction in its accessibility settings. It changes everything on the screen, not just one game, and it can rescue a game that ignores the problem.

How to check a game before you install

Look at the screenshots in grayscale. Most Android phones can switch the display to grayscale in the accessibility or Digital Wellbeing settings. If you cannot tell the pieces apart in the screenshots, you will not in the game.
Search the description for "color blind", "colorblind" or "accessibility". Developers who solved it usually say so.
Search the reviews for the same words. Players who could not play say it plainly.
Check whether the support is always on or a setting. Both work. Always on is a sign it was designed in, not added later.

Other things that make a game easier to read

Color is the most common problem, but not the only one. A few more details decide whether a game is comfortable for players with low vision or simply tired eyes:

Pieces large enough to read and tap without zooming, on an ordinary phone.
Strong contrast between the pieces and the background.
Sound and vibration that are optional, with nothing important told only by sound.
A setting to reduce motion, for players who find fast effects tiring.

How our games handle it

Every Hopvera game follows the same rule: color never carries information alone. In our four games it looks like this:

Glassful, our color sort game, gives each of its ten colors its own symbol: circle, triangle, square, diamond, plus, star, ring, hexagon, wave and bars. You can sort by shape alone.
Solitaire shows a clear rank and suit mark on every card, and the suits are told apart by shape, not only by color.
Scootle, our arrow puzzle, gives each direction its own color, but the arrow shape always shows the direction too.
Blockful, our block puzzle, uses color only as decoration. When a shape will not fit, the game shows it with motion and a preview, not only a tint.

All four are in development and not in the store yet. If anything in them is hard for you to read, we want to know. Write to us.