painting khorne red over mephiston red spray

so i want to paint kabal of the flayed skull which basecolor is khorme red. in pretty mich every tutorial they undercoat with chaos black but isnt mephiston red way easier when i want to apply khorne red as a base

If you go for chaos black, you'll need 2 thin coats of khorne red.

Might need only one on mephiston.
You might also get a brighter final result with mephiston red.

Make some tests