after several months of using my Colemak Shift-DH layout, I have finally arrived at a tri-coloured keyboard layout which highlights the modifier, home row and function layer—left number keypad and right navigation cluster (see Colemak Shift-DH for the function layer layouts)—key regions..
`~ = 1 2 3 4 5 6 7 8 9 0 [ ]
Esc - Q W F P B J L U Y ; ' Del
Tab / A R S T G M N E I O Enter
\ Shift X V D C Z K H , . Shift
Ctrl Win Alt Space Backspace Fn Pn Ctrl
It looks weird in coloured type but surprisingly works IMO with dark grey modifiers, light grey function layer and biege alpha keycaps. The visual symmetry of this particular layout is evident in many ways— an unexpected bonus to its ergonomic effectiveness.
The common index finger home row heys with a physical bump out (bar or nipple) or indentation (scoop) have been replaced with regular dark grey keycaps instead. This feels much better to my index fingers, even if an initial glance is required to position the hands in their home row position.
The Space bar and Backspace key are biege but look lighter from this angle due to their inverted position for a more natural thumb contact (as are left Ctrl, Alt and right Fn keys of the bottom row).
The contrasting home row keycaps also provide a visual reference point for the adjacent keys of multi-key combinations—which have not yet been instilled in my touch typing memory. Similarly, I have alternating light grey keycaps in the number row for quicker visual reference— most useful again for the (modifier combination) numeric function keys.
Why the use of blank keys and coloured keycaps? The Colemak Shift-DH layout moves several keys out of their QWERTY row positions. Unless you are using keycaps that have a uniformly flat profile such as DSA profile, shifting printed keys out of their row positions would impart physical changes to the row they land on. Also, even with a flat keycap profile, the modifier keys which cannot be swapped, would have incorrect legends. And the inverted bottom row keys would have upside-down legends! Besides, blank keycaps are just more aesthetic!
Armed with a keycap puller and more keycaps than most people have invested in their keyboards, there is no end of creative possibility!