I'm writing a program for recoloring vector/svg icon packs on the fly. Just got monochromatic working and applied it to the entire Papirus icon pack. If anyone is interested, check it out on GitHub. Request are welcome and stars are appreciated.
Looks better, but every time I tried it it didn't work for me so much. I noticed that I associate an app with its color, and that it's easier for me to look for something orange when I'm looking for Firefox than just the shape of the logo. This is one of the reasons why I hate Google Icon designs which basically use the same colors in their designs. Might look more aesthetical, but for me at least it is less practical.