Thanks for the recent columns on Trilogy of Terror, Don' Be Afraid of the Dark, and Salem's Lot...all three scarred me for life when I was 10. I remember Horror Week on Channel 7's 4:00 Movie in Washington DC featuring the first two.
Anyway, I hope that someone can help me find this terror. I don't know if I'm making it up, or misremembering, or conflating multiple movies, or what. It may have been a TV movie.
I seem to remember a story involving sisters and painting. In the story, one of the sisters somehow gets shrunk to a tiny size, like smaller than a thumb. I think she had long blonde hair. Eventually the other girl squishes her under her shoe and uses the resulting red goo as paint on a canvas. This scene sticks with me. Was it a movie, or a horrible dream?