How to prevent material being applied when filling holes?

I actually have two questions…

first, is there a way to prevent a material from being applied automatically when filling holes? In the image below, you can see part of a large triangulated shape with a brown material. I want to fill in all of those outer polygons and then give them that yellow-tan color that some of those faces already have, but when I use “fill holes”, all of the newly filled-in faces automatically adopt the brown material. If it wouldn’t do that, then I could just shift+g select similar one of the brown faces and then inverse the selection to apply the yellow color to all of outer polygons at once.

My second question, is there a way to select the complete outer edge of a 2D shape like this? Edge loop select doesn’t work, and it’s a real pain to select all those edges manually…

Select all - Select Boundary loop should get you outline selected. You could create temporary vertex group selecting brown by material and assigning that to group. All what would be left is deselect this group after you’ve filled holes.

Once you’ve selected the boundary vertices, make sure you’re in Vertex-select mode (not edge or face) and press Ctrl plus the “+” key on your numeric keypad. This should effectively select the outer ring of faces, at which point you can assign your other material to them.

Thanks for the quick replies and useful info! Boundary loop selection was a new one to me.

…and I don’t know why I didn’t think of using a vertex group for the brown part before.

I’ll just ask this here instead of making a new thread, since it’s related to the image I posted above -

What ways are there to fill a multisided polygon like that brown one with similar-sized triangles/quads?

The brown shape was triangulated normally, but what if I wanted a result where all of those inside faces were similar in size instead of having such long edges span across the entire length of it? I know I can play around with the dynamic topology tool in sculpt mode to subdivide the larger shapes, but is there a different way?

Except maybe manually Delete - Limited dissolve to get n-gon which you then cut in smaller parts and triangulate - idk there is much more.
Considering you’d like to keep outline not much changed, even less, i think.

Yeah, I figured it might come down to a manual process. At least doing brownie-style cuts across the whole thing as an n-gon and then re-triangulating doesn’t take too terribly long, and the results from that method are pretty close to what I’m looking for.

Thanks again for the tips.