Shapes:
I'd avoid duplicating the shapes already used on the chips. Star, circle, triangle, diamond, and square have already been used. Go with new ones for the plaques... like the oval and the rectangle. And don't overdo it -- simpler is better.
Colors:
In my head (always a dangerous place), I generally think of 25K chips as red, blue, or white (or all three, flags). Pay no attention to the many dark green 25K chips in existence. Since your chip colors already include a white chip, that's out -- leaving red or blue as my choices for a T25K, and with a pink T5000, I'd go with bright blue. For the T100K, either red or yellow will compliment the set nicely.
Design:
First off, all of the denominations on the plaques should face inward, just like on the chips.
Second, all of your chip denominations are placed at 1:30, 4:30, 7:30, and 10:30 locations. Putting them at 12, 3, 6, and 9 o'clock on the plaques just looks wrong. Put the denoms in the corners of the plaques.
Third, the plaques need to carry on your trademark "WC symbol in a circle" concept. Each chip has the WC symbol, surrounding circle, and "Windy Crest Poker Room" text using three colors, which are also used as the three colors for the chip base, denomination, and style shape. Keep that same concept on the plaques. Personally, I'd use two of them on each plaque in the center area, with one facing up and the other facing down -- so it looks the same no matter from what direction it is viewed.
Lastly, because it doesn't match the chips, I'd ditch the playing card mountain range graphic. Stick with what works well on the chips, and the plaques will match up much better.