How do I make red buttercream frosting that is really vibrant?

Chefmaster liqua gel colors. Very vibrant and no waiting for color to intensify. Also no bitter taste. That's what I used for the catsup on my hamburger cake (in my photos) it's very vibrant.

Use any that has the word 'super' in it....like "Super Red"...
Americolor seems to work great for me. Chefmaster is good too.
Start w/a base color like pink or orange before adding your red color paste/gel. Make it the night before needing it. Color intensifies when it has time to sit.
If you can stand flavoring in the icing....add about 1/4 to 1/2 teaspoon Black Cherry KoolAid powder (UNsweetened). If you do this you have to make it the night before; when you look at it the next day it probably will have many, many dark spots; just stir it well and it will be perfect

I always make red by colouring my icing a dark pink first and then adding the red from there. It's easier to get a nice red from a pink base than from a white.