lite colours first, than a very subtle shading of the same colour in a slightly darker pigment, test the colour combo first on a blank page, one wrong step will fuck you up because the colour on the cap of a pen (or any type of paint for that matter) usually does not indicate the true colour of its contents. seriously though, when combining the same shade for a shadow/depth perception subtlety is a MUST. its what you dont see at first that stands out when you look at it closer. same applies to music, sometimes the baseline is hidden but without it people would notice an incredible absence. hope it comes out to your satisfaction.