Based on Gorilla’s data which shows what colors have NOT appeared here are the % for color of each block we have YET to see.
Keep in mind, for some materials this is not accurate. For example…sand can be made from rocks which may have appeared in a color the sand has not appeared yet…and rocks can be block changed. But just based on this list of what hasn’t appeared, here are the percentages we have not seen in the universe in almost 2 years.