Here is the chart I have put together with the colours I usually blend together... for these colour swatches I have imagined the light source is at the bottom right of the screen so that is where the lightest colour would naturally be... getting darkest at the top left of the colour swatches:
The instructions for the skin .... (which it turns out are too small to read here unless you are Superman!) .... say to use a small acrylic block and scribble on about 2/3 of it with the Soft Suede and then on the remaining 1/3 of it with the Calypso Coral. Use the blender pen to combine the colours and then use a scrap piece of paper to lose some of the intensity of the colour before using the blender pen to colour a very light version of the mixed colour to your stamped image. (Adjust the ratio of these two colours to get a more or less brown toned colour.)
When finished colouring the skin tone you can clean the block and then using just Calypso Coral from the block onto your blending pen, again use scrap paper to lose the intensity of the colour before using it, add just to the cheeks as a hightlight.
If you haven't seen me colouring recently, this is a great video that I found online that explains how to colour in using the markers.... (Note: Where I use the acrylic block to scribble some marker on before picking it up with the blending pen this video shows using the plastic box the markers come in to scribble out some marker colour .... really you can use any non-porous surface you have to hand for this purpose.)
Now, remember that the Stampin' Up! markers are water based so stamp your image using Staz-On ink first so that the stamped image does not bleed. Also, if I had remembered to buy some Watercolor Paper when I put in my last Stampin' Up! order it would have made my life much easier... but I persisted with the regular Whisper White cardstock and was happy with the blended colours.... why do anything the easy way? lol So, grab out your markers and come play along with me... this is one of those techniques that gets easier with practice. Share with me what you have made.... I love seeing what you create.