Mix it a day ahead if you can because it will darken. Start off with pink maybe to at least get it tinted then add red and let it sit. It will darken as it sits. Then add red again to achieve the color you want.
I would go all red then add a tiny pick of orange to it. That red in the photo looks more on the orange yellow side of a colour wheel to me!
Hi. Like Karema said, if you can, let the color develop (couple hours to overnight). I had this happen with the red I used on a train cake. I made and assembled same day. The caboose was a shade of pink and I was disappointed with it. But when I got up the next morning, it was bright red indeed!!!
Also, I like to keep a color wheel handy, as banba mentions. It's extremely helpful with mixing colors (when the shade in the bottle just won't do).
Good luck with your cake!
Yes, there are many posts on how to make bright or deep red.
You do need to mix up the color ahead of time......best at least the nightbefore.
Start w/yellow OR orange OR pink.....make it a nice, vibrent color before adding your red. By starting w/a base of orange, pink or yellow you will use much less red so it won't develope that nasty taste. Liquid gels are great as are Americolor.
The other thing you can do - if your icing can be flavored - is to the base color add about 1/4 tsp. UNsweetened KoolAid (I like black cherry; some say strawberry makes a better red). Mix this in very well and let it sit overnight. When you look at it the next a.m. it may well have dark spots. Never fear......just stir it up well and it will blend just fine; the spots will not come back