Blue LEDs are all made with “modern” ultra high efficiency compositions. Red, yellow, and green (especially yellow) are often older, less efficient chemistries. (Modern emerald green LEDs can be insanely efficient. As power indicators, I usually run them at about 0.5mA.) The result is that at a given current, the blue LED can be massively brighter.
You can get a sort of broad idea as to the chemistry by the forward voltage: for a given color, a higher voltage tends to be more efficient. So for example a traditional green LED might be 2.2V, while a modern high efficiency one is 3.2V.
In any case, I totally agree with the recommendation to do some testing and basically adjust it by eye using potentiometers until you’ve found what values work. Between LED chemistry, human eye characteristics, and optical characteristics of different LEDs, there’s just no real way to rely on calculations alone.