Blend modes with blend and tblend filter:

addition	and	average	bleach	burn
darken	difference	divide	dodge	exclusion
extremity	freeze	geometric	glow	grainextract
grainmerge	hardlight	hardmix	hardoverlay	harmonic
heat	interpolate	lighten	linearlight	multiply128
multiply	negation	normal (all_opacity = 1)	normal (all_opacity = 0.5)	normal (all_opacity = 0)
or	overlay	phoenix	pinlight	reflect
screen	softdifference	softlight	stain	subtract
vividlight	xor

These images can be made with these command lines:

ffmpeg -f lavfi -i color=s=256x256,geq=r='H-1-Y':g='H-1-Y':b='H-1-Y' -frames 1 -y test.png

ffmpeg -i test.png -vf "split[a][b];[b]transpose[b];[a][b]blend=all_mode=harmonic,pseudocolor=preset=turbo" -y harmonic.png

These are the input images before and after transposing:

test.png	test_transposed.png