According to GARF, coralline thrives in deepwater regions where the light is dim and blue, that's why they say actinic promotes coralline growth.
But IMO, the most important element that you need most is a high Mg amount.
And since coralline is a form of algae, I believe that it also needs a form of lighting to grow. I have been very successful using GARF's methods, boasting red, orange, green, pink and purple coralline all over my tank