"It will certainly brighten up a wall, but the Colourblind Clock by Sono Design offers a little more.
Like a puzzle. Yes, there are numbers on the clock, but they’re not obviously visible. You’ll have to look very closely to pick them out.
Aside from the hidden numbers, you also get that splash of colour on your wall, printed onto double thickness high quality acrylic.
Yours for £45.”
Design Museum website