Default color type is wild type. All the other major "colors" are caused by recessive genes, that is, you need two of that recessive gene to get that color. So, 2 leucistic parents will have all leucistic offspring. But the colors interact in some non-intuitive ways, so an axie that is both leucistic and albino will look white with pink eyes, with maybe some yellow freckles.
Because wild type is default, and all others are only seen if the individual got two recessives, it is hard to say what you will get when you breed axies of different colors, unless you know more about their genetics. Since you got albinos, both of your axies have albino recessive genes. Since you got melanoid, your wild type has a melanoid recessive.
GFP is a dominant gene, so one GFP parent results in 50% or 100% percent GFP. (If the parent has 2 GFP genes, all of its offspring will get one, and so all will be GFP). 2 GFP parents will have 75% or 100% GFP offspring.
Axolotls - Genetics and Colour has some basics.
Those unusual new colors like purple and copper? I don't know about those. I look forward to hearing more when people figure it out.
And then there are the chimeras, that are genetically 2 different axolotls that just happened to merge early in development. You can't breed for that - it just happens. :happy: