What is White Cumin and Green Cumin? I'm learning about the spice cumin (Cuminum Cyminum) and I understand how it is naturally a golden brown color seed that tastes bitter with a hint of lemon and warmth.

I learned that black cumin (Nigella Sativa) is a different plant all together and has a black pepper and oregano taste.

What I can't figure out is the other two color cumins.

What is Green Cumin? Is this an unripe cumin seed picked early? I see it referenced in Iranian cooking but I haven't found out what plant this is. It seems like Persian cooking uses both black and green cumin frequently.

What is White Cumin? Is this a sun bleached cumin seed left out to lose its color? Does it have a milder taste than regular cumin or is this a different plant all together? I see White Cumin listed in Indian cooking.

If anyone knows what Green Cumin or White Cumin are and can cite the plants or any references to them I'd be much appreciative!
The question is "what is language and why the people cannot stick to one original name?" ;)

What could be find under "white/sweet cumin" is actually aniseed (and sometimes it's called green cumin). What is "green cumin" is dill seeds. 

The way to go is to look for latin name or the look of it. What could be more troublesome is difference between Roman Cumin and Persian Cumin (very, very very often treated as same thing). Roman cumin is much more mild than Persian (or sometimes even called Turkish) one.  

White cumin might be regular cumin just looking "whiteish" because of the place of origin but might also be aniseed but it could be lost in translation of the recipe.