On the topic of rolls:
I'm supportive of getting some of the information out of the combat log, into combat itself. What matters is that it would be quick and not slow down combat (sans clicks). The player already confirmed the attack with clicks, that should be the trigger to roll/show dice.
I think it'd be simplest to show the d20 outcome and the damage dice outcome as the attack animation plays. I'm also open to a quick animation where it's mostly the end of the dice roll. (What's important is that it can finish during the attack animation).
As for changing dice color:
That'd be a cool nice to have. Even if we had to wait until after release for dice colors, I'd enjoy it.
It'd be preferable to select dice color in character creation, I like making red-headed characters but with the d20 being red it can be too much red on screen. I've switched to green hair for elves, etc.