Eishiya, sorry for the late reply, busy holiday around here. This is a mockup which shows some of the difficulties of repeating colors, which, as you mentioned, can be solved by other factor on final tiles, such as detail and textures, since the current tiles are basically only a height map to help visualize forms and proper collisions:

I'll have to redraw most of the actual tiles with proper detail in order to match isometric view (was previously working with 4:3 rectangular tiles only).
Curly, thanks for the reference, I'll look into other games with similar shapes, and I do remember a sonic game with isometric tiles which might have something along these lines