These layers will go under your pixel layers, immediately above the Background layer.
First, a Channel Mixer layer, with "Monochrome" checked, at 0, 0, +100, 0. This will make the whole carpet and bricks and dress grey. You can include bricks and dress in your selection.
Then, clip a Levels layer to the Channel Mixer layer:
R 0, 1.00, 255 and 185, 230
G 0, 1.00, 255 and 55/245