Which brand of paper is it? Some graded papers respond to light filtration a little bit like VC. For example Ilford Gallerie can be manipulated about 0.5 grade up/down by using yellow (green) vs magenta (blue) filtration, with white light getting a half-way result.
It is Fotokemika Emaks paper. I have Ilford filters, and color head in Focomat V35.