I've just received my Vivomove Style and notice that the main text color is fixed as white. I have the silver face, so outside in sunlight, the white text on silver background simply disappears.
I don't know if being able to change the color from white to something else would solve the situation or not, but it would be great to have the ability regardless.
I also wonder if a solution might be, when the watch senses bright light, that the background of the entire display changed to a darker color (not sure the display has black, but that would be best), while keeping the letters white, so there was contrast between the foreground and background.