Change brush mask color

I’ve just started working with Optics (love it) and am pretty confident on my ability to understand the UI as I’ve been using PS professionally for 30 years however I can’t seem to locate how to change my mask paint brush color to achieve the opposite effect (hide) part of the effect. In PS I just swap black/white with the “x” key but not in Optics. I’ve looked in the mask settings and I just don’t see that option?

I’m sure it’s right in front of me and I’m going to face palm when it’s pointed out but I don’t see it and a search just came up with general masking help. It’s driving me and my workflow batty!

Hi, masks are black & white, there’s controls at the top for size & opacity of the brush,

There’s also an invert option.

Screenshot 2023-04-22 154803

Thanks for the reply. I guess I’m looking at masks from a Photoshop point of view because I don’t see a way to inverse the brush to erase or paint on the mask. It only seems like I can paint onto a mask. I know the entire mask can be inverted and the opacity of the entire mask can be dialed in by selecting the buttons on the mask toolbar but not the actual brush? Am I still missing something (or not understanding the controls)? Thanks.

It is a bit basic, multiple mask can be added, black you can see through white you can’t,
like i say & you’ve prob discovered there’s a few tools at the top but if you don’t like a mask you have to delete, an eraser or yes the option to swap the brush from black to white so you can recolour a part of the mask would be good,

PS I do like the Path mask & the EZ mask is ok, yeah different controls, In some ways i still prefer GIMP which is a lot like PS. but I’ll keep trying Optics & hopefully it’ll come more natural to use.

Much appreciated. Surprising that an advanced app like this doesn’t have more than basic masking (brush) tools. Thanks for the info!