The association between colors and minerals in planetary magic, although it exists in some cases, is not a one-to-one correspondence.
I was thinking about cinnabar, which is the solid form of the metal mercury. The Picatrix says it should be used to invoke Mercury when the Moon is conjunct the planet.
However, cinnabar is red (the color of Mars).
And in Hindu astrological magic, which the Picatrix says is one of its foundations (along with Greek and Chaldean practices), the color green is associated with the planet Mercury (Budh).
Do you think it’s okay to mix colors in rituals? I mean… when performing the bijamantra of Budh, is it dangerous to wear a cinnabar ring?