I should've taken a picture of it, but I did a little test on a protector sheet with a marker and when both dress and unicorn were faded it ended up looking kind of blobby because it lost some of the definition between dress/unicorn body. The only other solution that i could think of would be to make them opposite fades. (Unicorn = Blue to purple , Dress purple to blue)
The name of the picture is "Like You" so I wanted them to be matchy.
edit: Or I could make them both purple to blue, but diffeerent shades
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idk, I think my brain is getting more complicated than my actual skills XD