Looking for the perfect neutral - not brown or grey.

The sectional is "greige" - trying to set a neutral pallet so I can change out pillows/accessories in any color.I have tried SW balanced beige, diverse beige and accessible beige. All seem to go grey in certain lights. The fireplace surround is reddish marble. The piano, dining room set and secretary desk are all mahogany. Thinking of ordering a big print (Antelope Canyon?) with shades of orange, red and yellow. Maybe something wispy on the windows. I can not figure out how to post more than one photo at a time. More to follow.