I think the meant only that your darker pink seems much lighter than your darker blue, not in a mathy way. I will never try to derive calculations for color values to define palettes again. The last time I did it here I ended up with a lot of unusable shades, and got a nice earful from cyangmou on how each hue has its own quirks regarding saturation and value, so instinctive perception of equivalence across hues is the key.