This can happen with incorrect color resolution settings. Try moving your color settings to a smaller value.

On a PC, use "Medium (16-bit)" instead of "Highest (32-bit)" color quality in Start > Control Panel > Display > Settings > Color Quality.

On a Mac, go to the Apple > System preferences > Hardware > Disaplays and move the "Colors" setting down to the next level (for example, from Millions down to Thousands).