It looks nice in my opinion. 
Thanks for making the mockup! For what itās worth, Iām glad that the caret and selections are the only orange things in the score - it makes them easy to find. If the caret could change colors it would be harder to see it, in my opinion.
Voice colours in Dorico donāt have any real significance, beyond it simply being possible to tell multiple voices apart. I wouldnāt be in favour of updating the colour of the caret to match the current voice. The caret already provides you with a visual indication of which voice youāre inputting into.
If I may add to that: colors arenāt the best way to convey meaning because not all people are made equal, and some have problems differentiating colors or various shades thereof. This can even be a problem for ānormalā sighted users with the advent of applications that change the color temperature of displays (e. g. Night Shift or f.lux).
I do miss the predicatable colours assigned to specific voices in Sibelius. It is a very useful feature, particularly for keyboard music, which often requires four or five voices on a stave. I dont care what the colours are, as long as they are consistently applied in this way.
David
Like david-p, and for the same reasons, I very much like predictable colours assigned to specific voices.
They are predictableāif you enter your voices in exactly the same order every time. 
Indeed.
Iād love persistent voice colours. I still get caught on two stave instruments.