I too tend toward muted tones, sometimes with a spot of bright color as a butt, during low-water of mid-summer to early fall. Flies like the March Brown, Sweep, Lady Caroline, Blue Charm, Logie, etc. tied true low-water style on #6 or 8 low-water hooks are some of my favorites. I also carry a few small, bright, sparkling flies in summer. Flies like the Cut Silk Shrimp, Kelson's Sun Fly in red, purple, or orange, and Silver Blue are always in my summer boxes. Small Ally's Shrimp in orange, black, and purple, the Night Dancer tied in Irish Shrimp style, Arnold's Spade, and a few steelhead spiders in black or purple, and a Spade tied with hare's ear dubbing (making it look a dubbed body Burlap).
These flies along with Lemire's Grease Liner in black and burnt orange, McMillan's Steelhead Caddis in orange, bombers in natural and black and yellow, Lanie Waller's Waller Waker, Wagoner's Wag's Waker in purple body with grizzly hackle, and Mark Pinch's Riffle Dancer make up the flies I use in summer.
In winter I prefer using the Glasso spey flies; a blue and red spey fly I call the Cop's Lights; a Don Kaas spey fly calledd the Red Knight; Ally's Shrimps in Orange, Red, Purple, Black, or Pink and Orange; Cinnamon Wing Akroyd with orange rear body; Price-Tannat's Avon Eagle. Kelson's Kate, Kelson's Purple Emperor (one of the best flies I've ever used for winter steelhead); Kelson's Floodtide, and perhaps the G.P. with hot pink added to tail and a face hackle of hot pink.