It's more like if you see that 130-ish palettes have little effect on some of the characters (the effect of the palette really depends on class sometimes. Mage, Acolyte, High Priest and the peco on swordie classes are prime example how only very rare palettes affect them), then is adding random palettes going to do much of an improvement for these classes? Currently most of the recent addition to palette are only higher quality products that does change the palette on most if not all classes, including the wedding dress sprite (which is a nightmare for all palette designer to get a palette that doesn't screw up the dress.) So it's not that we aren't aware of there being so many colours, just that Panda didn't pass them and gave most of those other palettes a "fail grade" so they didn't make their ways to the server.
However, I really don't know what panda has in stock for palettes... her data file of potential customs deserve its own hard drive