This has possibilities but needs work!
How it was done.
Roller some acrylic paint onto your gelli plate using a brayer.
Place your stencil over the top
of the wet paint
Take a print by rubbing a piece of paper over the stencil.
Leave the stencil on the plate.
Gently lift the stencil to reveal the paint on the gelli plate. Leave to dry. This is very important. I didn't and ruined my print!
When the paint is thoroughly dry, squeeze some acrylic paint using a 3rd colour onto the plate. Roller on with your brayer. You need a very thin coat of paint, so clean the brayer between rolls on a piece of scrap paper. You should be able to see the colours through the top layer as in the photo below.
Take a print and rub very thoroughly on the back of the paper.
Because my paint wasn't thoroughly dry the yellow ochre paint didn't lift onto the paper, but stuck the paper to the gelli plate instead. It wasn't too bad as an experimental piece, and I can remember to do it properly next time!