It will certainly brighten up a wall, but these Colour Clock and Colourblind Clock by Sono Design offer just a little bit more.
If you don't know yet what colour to paint your walls in, get the Colour clock
If you wanna make it a little bit more difficul, like a puzzle, well there are numbers on the Colourblind Clock, but they're not obviously visible. You'll have to look very closely to pick them out.
by Sono Design