Pharoah/Coturnix/etc are all the same type of quail. There are different _varieties_ of the quail (colors), but they all interbreed and are raised the same way.
The only real difference is going to be the A&M Texas quail. These were bred by A&M Texas University to be an all white meat bird and will have a different flavor than the other Coturnix - but they're still considered Coturnix quail. If you want a dark meat bird with white feathers then the British Range are for you.
Honestly, the different colors are mostly to be pretty. I've seen some people brag that the Manchurians are better layers, but that's going to be an individual strain, not the color as a whole.
Your white speckled Tibetan is probably from a mixed breeding. That or just a mutation. If you were breeding for color you'd cull him out. Unless you wanted to make him more speckled, get it to breed true and make it a new variety. I have some speckled Tibetans I'm playing around with right now
As far as the different varieties go, these are the ones I can think of offhand:
Brown (Standard color)
Manchurian/Speckled (Lighter mutation of the brown)
Ginger/Orange (Lighter mutation of the brown with no black speckles)
Tuxedo (Dark with a white throat/chest)
Tibetan (Dark mutation of the brown)
Black (Ask Sam. He's one of the few people working on this color)
British White (White with black specks on the head)
A&M White (Large white with black specks on head - all white meat)
Pied (People who have crossed whites with another color and have patchy offspring. I'm not sure anyone actually counts this as a separate variety as of yet.)
There are other funky colors and patterns people are fussing with. I have some fawn hooded whites I'm waiting on to see if I can get them to breed true and wanted to do a reverse pied using the Tuxedos, Tibetans and Manchurians (or Whites).
Good luck with your quail
The only real difference is going to be the A&M Texas quail. These were bred by A&M Texas University to be an all white meat bird and will have a different flavor than the other Coturnix - but they're still considered Coturnix quail. If you want a dark meat bird with white feathers then the British Range are for you.
Honestly, the different colors are mostly to be pretty. I've seen some people brag that the Manchurians are better layers, but that's going to be an individual strain, not the color as a whole.
Your white speckled Tibetan is probably from a mixed breeding. That or just a mutation. If you were breeding for color you'd cull him out. Unless you wanted to make him more speckled, get it to breed true and make it a new variety. I have some speckled Tibetans I'm playing around with right now

As far as the different varieties go, these are the ones I can think of offhand:
Brown (Standard color)
Manchurian/Speckled (Lighter mutation of the brown)
Ginger/Orange (Lighter mutation of the brown with no black speckles)
Tuxedo (Dark with a white throat/chest)
Tibetan (Dark mutation of the brown)
Black (Ask Sam. He's one of the few people working on this color)
British White (White with black specks on the head)
A&M White (Large white with black specks on head - all white meat)
Pied (People who have crossed whites with another color and have patchy offspring. I'm not sure anyone actually counts this as a separate variety as of yet.)
There are other funky colors and patterns people are fussing with. I have some fawn hooded whites I'm waiting on to see if I can get them to breed true and wanted to do a reverse pied using the Tuxedos, Tibetans and Manchurians (or Whites).
Good luck with your quail
