Originally Posted by JHarford
It's my understand I can't make a selection and then apply a fliter to it. How would I go about adjusting Hue for a selection on a patch. ?
Try this workaround and see if it works for you. Make your face selection, set the projection mode to Selection Only and switch to the clone brush tool and set it to registration mode (CTRL + Windows/Meta key + LMB) - using the the clone brush like this allows you to "pull" paint from the object back up into the paint buffer so you can edit it. Once the paint is back up in the paint buffer open up the filter (Hue) and set the operation to Current Painting. Once you've applied your filter, bake it back down onto the object.
The registration mode on the clone brush is really handy, but it can be tricky to know what your pulling up into the paint buffer - I set the paint mode to 'color burn' when painting and switch it back to normal once I'm done pulling the texture off the model.