Note that one of the discussion items on the Trello board is "unification of floor values" - Dave Collins was pushing for this. We might want to think about that in this context.
Outside of @bwoshea 's point about floor value unification, this one looks good to me.
Looks good. I'm guessing that none of the test problems use a color field with a value below the floor. I'm guessing it has John tested with values below that?
I had some species fractions (H2I and H2II very close to a radiation source) that were around 1e-20.
I think the unification of floor values is outside the scope of this PR, so I am accepting.
Would it be possible to replace the 1.d-35 with a variable called something like color_floor, so it's easy to find when we do unify the floor values? I agree that it's formally outside the scope, but we can make things easier on ourselves later.
It doesn't hurt to add a define with color_floor in this instance and add the other places where we floor the colors and species fractions later on.