Excellent observation. I don't think it has been brought up before.
I don't have a clue. But I will say the 'red' color between Indian-
Ceylon-Africa teas and the traditional Chinese red teas is quite
noticeable. The Indians are tan brown and Chinese almost a blood
red. I think what you see is absorption of this difference due to
curdling. Another possibility are the tannin levels which would act
as a pigment with the milk. I'd pay attention to the 'slick' or
'sheen' that can be seen on the tea surface in reflected light. I'd
guess the Indian teas are producing more and the Chinese less just
because Indian teas are good for one pot and the Chinese reds possibly
more than one.

Jim

PS I drink my teas nude and sometimes that way myself but I'm darn
careful.

Melinda wrote:
> Well I don't think I've seen this discussed here before so here goes: I
> usually drink my red teas with milk and sugar. When I do that I have noticed
> that the Assams and Ceylons and the African teas too are a sort of a tan
> color while the China reds (keemun, yunnan, and kind of congou) have a
> greyish cast to the color of the liquid (this is with milk). Has anyone else
> noticed that and what do you think causes it?
>
> Curious,
>
> Melinda