So, what I see from this interesting thread is that arms and armor were varied as was dress. Colors could be anything. Likely, the pro Marcher Welsh looked a lot like their English allies/lords. The native Welsh probably had somewhat more “antique” equipment but maybe not overly so. I cannot disagree with any of it. I think, in the end, pick some figures of the period that look right to you and go with it. Surely there are some figures of men-at-arms types of the time that are at least dressed in hose that would fit the bill?
"Nearly all men can stand adversity, but if you want to test a man's character, give him power."