You could get an area rug to layer on top of the carpet if you can't take the carpet up. The rug can provide the palette-you draw the colors out of it for other items like window treatments, pillows, etc. Basically find one thing with a pattern/color you love, then work from there. It can be something as small as a pillow.

Gray works with warm colors too. Choose a color you like and search for an area rug and pillows with that color in the pattern.

I'd love to do that but I was worried a accent rug on top of wall to wall carpeting wouldn't look right. First I need to decide on the color of the main carpet. Gray, beiges, whites, browns, taupe...I don't know which way to go. Thank you for your suggestion!