I cants understand what the problem is it keeps on asking to make header colour to gren
Okay, so I found the issue after looking for a minute... You're using the Canadian spelling of "colour" when you should use the American spelling which is "color".
Other than that the line is fine (tested it on my own course).
Always nice to learn to learn something, i always say that color is American and colour is British, but colour is also canadian? I think that should resolve the issue, good answer @terarunner93185
Color is American, and colour is British. Other English-speaking countries use one of the two spellings (usually British), but it is still technically the 'British spelling' (Coming from a Brit.)
thank you everyone that worked