I've got a large space, about 1/4", where my bathtub tiles almost reach the floor tiles. I'm filling that with flexible caulking but I only have a limited amount that will match the existing grout on the tiles above.

My question: can I fill in the majority of this space with a different colored flexible caulking, which will not be visible, let it cure, then apply the matching, limited amount caulking over that?

I'm concerned this thinner top layer may not adhere to the thicker bottom layer.