I was trying to figure that one out...
I wanted a adjustable Pin...but you already have that... it's just not very accessable...I was thinking of smaller panels of related colors I don't know for sure.
I just had a thought though...could you change the "Pin Area" to display little squares of colors in a fly over menu fashion so you could put like 50 colors on the tab and then pick the pin you want from the colors...like in a 5X10 grid. Then you could set up colors by lightness values or whatever you wanted and have more than 1 pin to choose from...
So the way I see it would be...Hover the mouse over a pin tab say "light skin tone" and when the mouse hits the tab a small flying menu opens with 5X10 color swatches on it and you click a swatch and it sets the pin color for you to drag to the spot you want. No pin would be created until you chose the color you want. <click> then the mouse becomes a pin. You select the spot on the image you want to adjust <click> your mouse changes back to the arrow, and you leave a Pin on the image with the color you picked set.
This would give me faster access to larger amounts of pins and more freedome to choose a color rather than trying to adjust the pin. I could have more presets to choose from. And i could create sets of colors for skin tones that are "family"
Greg