The megapixels have nothing to do with the color balance of your pics. Color representation in your pictures have everything to do with the color temperature of your lighting and the white balance setting in your camera.
The manual for your camera should give you an idea of what preset color temperatures you can set and should give you instructions on how to set it manually.
Generally, manual white balancing involves pointing your camera at a known white object and either capturing an image or having the camera set the white balance.