Spine tint, change color? (SOLVED)

Can you please clarify this.
I have a spine model with this special FP. If I manually change the tint constant in the .material file it changes color - so the shader works.

I don’t really get how I can update the tint variable though.

I tried writing

go.propery("tint", vmath.vector4(1,0,0,1))

at the top of the GO that holds the spine-model but it didn’t work.

I’ve updated shader constants with Sprites using sprite.set_constant, but there is no spine.set_constant?