This is a fun challenge! I had thought at first that “monochrome” in photography meant black and white. It’s good to be aware of opportunities to be blue on sky or golden on yellow. (I feel blue on grey skies often, myself.)
Monochromatic
Twisting tendrils pulsing poison
Bloody Portuguese placenta
birth marks and umbilicus
bruises rhyme with purple wine
capillary coupling
People eaters robed in splendor
Atmospheric skies at sunset
mussels in deep, hazy rain
eggplant mountains majesty
purple cows and penitents
Pimpernel-ish violet babies
Lilac lavender suspension
(dot, dot, dot) of disbelief.