> If I remember the keys on the keyboard reflect the colours on the board so that distinguishes it meaningfully (?) from on screen keyboards.

If a clone makes the game board and the on-screen keyboard use the same colors for a functional purpose, such as helping the user be less likely to use an incorrect letter on accident, then there should be no copyright issue with the matching of the colors between the game board and the keyboard.

The only copyright issue should be with the actual colors. A clone should not use the same colors that NY Times used. A clone should've used a different color than yellow for "right letter, wrong position" and a different color than "darker grey" (in dark mode, not sure about light mode) for "wrong letter". (Green for for "right letter" should always be fair game.) Simultaneously, the clone should be allowed to make the clone's keyboard use the same colors that the clone's game board uses.