changing colors in an image

I am designing a logo of the sun rising over the earth from the perspective of earth orbit.  The general look will be of the sun(looks like a star) illuminating a narrow crescent of the earth.  I am working on a picture, trying to adapt it for the logo.  I need to change the white sunlight to be yellow/red - can't seem to isolate the colors from the mix of earth colors or black background colors they mix with.  Another thing I need is to use a white background instead of the black background of the picture taken from space.  Is there a way to convert all the colors that are a mix of the black background and something else to be changed to be as if the background was white?

Any help is appreciated.

Chris