Pravana permanent vivid color

Hey guys! I have a faded red haired client who wants to go navy blue! My plan is to use Pravana’s permanent color line. I’m gonna start with the Chromo silk in ash blue to cancel out a lot of her warmth. Then I’m gonna go in with their semi permanent blue in the shade all night.

My question is has anyone used the Chromo silk ash blue as a direct dye? It is technically an additive, but Google says it’s OK to use it as a direct dye what are your guys’s opinions?