Colored fondant... what kind of food coloring?

Im tackling a project for Lily's birthday and making an AWESOME cake. I can post pics if you'd like. But for those who have made marshmallow fondant... what kind of food coloring is the best to make colors for the rainbow?

Are drop food coloring better than gels? Can you use any kind of coloring or is there a special type for this kind of stuff?

i wanna see  
and i've just used drops on marshmallow fondant.

when i make MMF, i use Wilton Gel because i've tried to get the perfect color and end up using almost a whole bottle of liquid dye  

I'd use gel. It doesn't compromise the texture/thickness of the fondant

Quoting KNZ.:" i wanna see   and i've just used drops on marshmallow fondant. "

Im attempting to make this:
http://livelearnloveeat.com/tag/my-little-pony-marshmallow-fondant-cake/

Is marshmallow fondant yummy? Will kids like it? Is there a better fondant to make?

Quoting FroggysMommy:" Im attempting to make this: http://livelearnloveeat.com/tag/my-little-pony-marshmallow-fondant-cake/ Is marshmallow fondant yummy? Will kids like it? Is there a better fondant to make?"

make MMF, its easy and tastes good. super sweet though! So it's like candy coated cake  

Quoting FroggysMommy:" Im attempting to make this: http://livelearnloveeat.com/tag/my-little-pony-marshmallow-fondant-cake/ Is marshmallow fondant yummy? Will kids like it? Is there a better fondant to make?"

i've heard it's the most edible-friendly fondant.
it tastes like marshmallows. the kid's at my son's party ate it.
that cake is adorable  

Gel works best. Drops take way to much to get a true color and the powder is super messy. Or you could be a cheater like me and have an airbrush   then it's SUPER easy lol

Gels are great. you only need a teeny-tiny amount.
I use a toothpick dipped in the gel to add to whatever I'm tinting as it has so much pigment. the toothpick allows better control.

Quoting Mommy of a giggler!:" Gel works best. Drops take way to much to get a true color and the powder is super messy. Or you could be a cheater like me and have an airbrush   then it's SUPER easy lol"

Id LOVE to have an airbrush... I make so many funky snacks that it would be AWESOME! But I need money for this damn party without any extras and the holidays... maybe soon though!

I'll post pics of the cake when I'm done. I think I have a good idea of how I want the design to go. I am going to make a tie dye layer over the tie-dyed white cake underneath. I found an awesome banana cake but I dont know if other kids will like it... so white it is   But the fondant will be tie dye, Im stoked!