I would guess: not enough Romans in Britain to have overwhelming impact on the local language.

As for colour, somewhere amongst my books I have an old pre-WW1 British Officers Training Manual which refers to both Indian and Scottish troops as Black soldiers, which strikes me as very odd or possibly very enlightening. Reminds me also of an Apartheid era South African man I met at a party once, who was involved in a huge argument with some of the (mixed colour) guests regarding his own angry insistence that he was white and had the papers to prove it. It was obvious to anyone that either his ancestry was almost certainly mixed race, or that he had inherited such a remarkable collection of 'white' genes as to appear to be a living physical testimony to the common (and recent) origin of all races. (The argument had started because of his obvious, and spoken, discomfort with the racial composition of the party.)

The more DNA testing that is done, the more we find we are all alike, and all closely related.