I googled 'black magic card technique' and got a number of hits.
It is stamping a solid image using white pigment ink onto black matte cardstock. When the ink is dry, you color the white image with the colored pencils and you can then highlight the colored image by outlining with a white pen or a sakura glitter pen or i guess you could use stickles or spica pens or whatever pens you wanted for the highlights.
If you repeat that google search, you'll get variations to the technique.
HTH and glad you asked - this is a new technique to me and the samples from the google search were really pretty