The few spring chinook I've caught were hooked on chartreuse comets (chartreuse calf tail, lime green braided mylar body, and chartreuse hackle, medium bead chain eyes), hot pink comet (hot pink calf tail, pink or silver braided mylar body, hot pink hackle, medium bead chain eyes), hot orange comet (hot orange calf tail, solver braided mylar body, hot orange hackle, medium bead chain) - I tie these on #4 and #6 stainless saltwater hooks.
My favorite for chinook, silvers, and chum a fuschia bunny tied on a heavy weight AJ spey hook #3 (body [also acts as the tying thread] is fuschia Unit-Stretch, wing/tail is fuschia bunny strip tied down above hook point and again just behind the hook return, then hackle the fly with 2 turns of the bunny strip after it is tied down behind the hook return, 3 strands each of hot pink and blue Kystal Flash on each side of fly tied in after bunny hackle is tied in and cut off). Very simply to tie and very effective.
The spring chinook I've caught all just picked up the fly fished almost dead drift on a sink tip in the throat of the hole. The takes were very soft.
Here is a scan of the fuschia bunny.