Vertex Color unreadable

Hi! I’m using an ‘Attribute’ node to pick my vertex color and filter the green spectrum to input to a coloramp. If I take the ‘fac’ socket as output it works fine, but then I lose the filter color resource. If I plug the ‘color’ socket nothing happens. I saw a video where it works perfectly fine, the same build I did here. What could be happening? Could it be the brush config issue? ! Also: Blendere completely ignores the existence of two vertex colors, it only applies colors and considers one.