[jasongi]

For accessibility, consider representing closeness without colour or shade of colour, maybe through a little number or something?

I think there might be too much information given away by disclosing how far away the letter is though. A more difficult mode could be just having three states:

1. Amber: Closest guess(es) so far 2. Red: Wrong guess that is not the closest 3. Green: Correct guess

So you only get new information after the second guess, assuming you don’t hit a green on the first go, and you don’t immediately eliminate most of the keyboard as soon as you are within 2-3 (haven’t quite worked out when the shading starts) characters away.