Ordering meta values for WP_Query?

Hello!

So I have a problem that I cant seem to find a solution to anywhere here or on other forums.

I have a meta_key lets call it ‘color’ that I am adding to certain posts. Lets say the keys are ‘red’, ‘blue’, ‘yellow’ and ‘green’.

Now I use a custom query to look for those posts with the meta_key ‘color’ using those arguments:

$args = array(
					'post_type' => 'project',
					'orderby' => 'meta_value',
					'meta_key' => 'color');

Now everything works as expected, but my question is how can I SORT the meta_values in a custom order. WordPress just uses them in alphabetical order so blue, green, red, yellow, but I would like to have a custom order so that I first get all posts with yellow, then green, then blue and then red.

Anybody have a solution for that?

Thanks so much!