"Staining" stage for the Glacier painting

Jim Lamb once told to students at a workshop to use more paint, or enough paint pigments, to cover the canvas otherwise you would be just "staining" it. But that's exactly what I'm doing now.
I just want to get some sense of color coordination at this early stage instead of committing to each color I put as the bottom layer. When I decided on this composition, I felt this would be more about the clouds than either mountains or the lake.