Modify a plugin

Bit of a cheeky question perhaps, but is it possible to modify a plug in that uses CSS?

I have a paid plug in, but keep having users complain about the readability. The colour scheme is the culprit and something I’ve been wanting to change anyway. I looked into the code and from what I can tell it’s all being controlled in a CSS file. Is there a way to modify that CSS file?

ps. yes, yes I should really ask the plug in dev. And I’m sure the owner of this plug in is a nice person. but I honestly haven’t heard back from a single plug in dev I’ve reached out to, so I’m skipping that step this time.

If the is attribute is available you could use the run JavaScript plugin from toolbox to add whatever style you want to any element.