That's actually done already in the my little darkness mod, He said he's holding on to the program he wrote to make the files tho, so i guess if you want to replicate that you have to do it manually or write your own program.
The biggest issue is that even with just ten extra castes of each type
(fanon is magic has 3*2*11+1 = 67) increases the file size of the entity to several hundred KB. The one for MLD was over a meg and a half last i checked,
(a month ago) and used a common description list per race, resulting in all earth pony males looking identical. Adding the colors on a per caste basis would probably add another megabyte to that.
Wether entity file size has any effect on the game running or not or if there's a limit, I can't say. But I can't imagine having the filesize 30 times of the intended file is very good
Edit: Telgin, you could identify your pony "class" by their cutie mark, pickaxe or shovel or mining cart would be better at mining and such. a flower or apple would be better at farming