I updated the layout drawing...
...If you have any advice about this, please reply in this thread
It looks much better with an "Enter" key vs the "Vista" key in the first image. The yellow on green alphas and modifiers look like an excellent combination.
I'm not sure about the particular orange color. Possibly it's too strong? I would play around with some layouts myself and see if there is a slightly softer, less intense orange to make a more constructive suggestion, but I can't find a reference page for all the colors GMK offer. Is there one?
Are you looking for suggestions on the key selection for the base kit and child kits? or are you just focused on the core concept and colors for now?