Leveling an alt and using skinning as a side profession. So, my understanding is that if it’s Red, unable to perform task and no skill up. If it’s Orange, possible to fail task and doing it over but guaranteed skill up. If it’s Yellow, most likely to perform the task and most likely to skill up but not definite to skill up. Green- always perform the task but not likely to skill up. Grey - always able to perform task but not able to skill up.
So with that info out of the way. The Pridewing Wyvern that are in Stonetalon mountains are orange for me to skin. However, noticing that I’ve killed quite a few and failed the skinning and performed the task over again… it’s not giving me skill up.