Golden Color Mixer
Okay, so this link above is kinda neat. Of course, trying it with real paint is going to give you better results, but you could still use it as a tool to help you on your way. I am sure monitor calibration is an issue, too. But still just fun to play with while your taking a break. And if you want to save a little on your paints, it may be a good starting point to test how to get to a certain color. How many of us have proceeded to mix a color and boy did it go wrong along the way.
Speaking of color, love the blue in the water. (Self portrait photo I was goofing around with up in Maine.) According to the color mixer, I may get a good match by going with either Cobalt Blue or Ultramarine Blue mixed with Manganese Blue Hue. Have to head to my studio and test it out.