My condolences to you about the loss of your mother. Losing your mom is very difficult, especially after a long illness.
As for the frame colors on your cow painting, the orange frame does bring the eye to the darker elements, and "corrals" the entire piece. In me opinion, the expansive nature of the yellow frame opens up ther entire picture. It gives you an open sunny feel, as it yo were standing in the meadow with the cow! Yellow for me! Good luck with the exhibit.
The orange does bring out the dark's in the painting, but is easier on the eyes, allowing for a longer look at the painting!
Yellow because of the texture and size of the frame unless the picture gives the illusion of the yellow frame being slightly bigger.
Orange makes the painting "POP". Yellow blends and makes ithe painting and frame over all "yellow". Beautiful painting!!!
I prefer the orange because it makes the darker orange colors in her coat really pop.