I have to say I like paste better myself, but I use the liquid more often ( application is much quicker ).
This is just an opinion from trying both a few times.
With red, if you are going with the layer look, I don't know if you would want to layer in Black Hole or White Diamond. I am doing a test fender on my Dark Stone F150 where I am layering in WD instead of BH, and I think it makes the paint look a bit more gray rather then closer to UPS brown that Black Hole does. I am using Natty's red for this test.
I would think Natty's Blue and White Diamond ??? Wait and see what one of the other members with more experience than myself have to offer.