I would just repair and refinish,
: but the thought of bringing the color back makes me want to
: re-glass completely.

: Does anyone know of a way to keep the wood from changing color?

: Pete

Most woods will darken over time with exposure to sunlight even through fiberglass and epoxy coatings.

Even bright colored woods like purple heart and padauk will turn dark brown over time.
Dark colors sometimes fade, and light colors darken.

I built a boat using dark western red cedar heartwood and light colored sapwood, thinking I would
have a nice color contrast, but over time the colors changed and there was little contrast at all.

You can applying new fiberglass and epoxy coatings and see the freshly sanded wood colors shine bright.
But the only way you can keep the colors from changing back to what you see now, is to paddle only at night!

All the best,
Rob