I've been testing nuophoto and have found out,
that if you choose color effect,
then remove created layer,
choose artistic and remove created layer,
and then try to choose color effect,
you will be prompted to choose parameter like radius or brush size (which color effect doesn't require),
and after applying it will create layer with last chosen artistic effect.
@JoHnYLucas Thanks for reporting, I'll probably redo the interface and the app at some point in Angular, to take away some of the complexity. This was done almost for fun as a quick demo.
I've been testing nuophoto and have found out, that if you choose color effect, then remove created layer, choose artistic and remove created layer, and then try to choose color effect, you will be prompted to choose parameter like radius or brush size (which color effect doesn't require), and after applying it will create layer with last chosen artistic effect.