In case your monitor is reading tans and beige be rest assured that the colors in my Madder Root on Vintage Trims post are in fact peach, coral, and orange! AND there's even a bright neon yellowish to orangish on the nylon cotton blend. NOTE that colors DO vary from monitor to monitor, and my monitor is set to CMYK mode.
While dyeing cotton fabrics does involve a certain amount of work bright colors CAN be obtained on cotton and linen fabrics! Don't be discouraged by what other's say bright colors ARE obtainable on cotton and linen. I've been dyeing cotton for over 15 years now and I'm living proof that it is indeed possible.