Nothing, except the nationality of the writer. Americans spell it color and generally, British people spell it colour, with a U.
There is no difference between "color" and "color." They are simply alternate spellings of the same word, with the former being the American English spelling and the latter being the British English spelling.
Black is darker.
There is basically no difference between Japanese hair and American. The only difference is the color, Japanese tends to have darker brown color, where as American have bronze color.
the color
Color
The Color.
color
I don't see any difference.
The difference is that there is an extra word
The main difference between white and purple eggplant is the color. On the inside, there is almost no difference in taste or texture between the two.
There is a slight difference in color, but a great distance between their countries of origin.
Cannot is correct. Can not is incorrect.