There was a Casio piano which had keys which lit up - not sure if that did 'keys' as well
but worth googling.
However, I would seriously question the value of what you
are doing. TTSTTTS is not radically difficult to remember and once you get the hang of
that, it's all plain sailing. There are other strategies as well - look at the standard
progression for 12 bar blues. It is 1-4-5, so for C, it would be C, F and G which results
in the notes C, E, G, F, A, B at the very least (think of the triads under your hands).
The key of E (as favoured by stringists) would be chords E, A and B resulting in the notes
E, G#, B, A, C#, F#, D#. etc. So for major scales, it gets easier. Then all you have to
remember is the relationship between major and minor scales (drop 3 semitones) so a key of
A minor would be the notes in the scale of C major. Simples.
coloured tape on keys, I would worry that you are limiting what you can do. I'm no
classically trained muso, but if a numpty like me can wrap my head around it, then
Oh .. and guitarists cheat and learn the pentatonic scale which only needs five notes
and spans multiple keys. And quite a few of them make a living from it ..
Veni, Vidi, Aesculi
(I came, I saw, I conkered)