Lightening up body coat color

[Jimd0586]

Hi all.

 

I am building a Revell 1968 Volkswagen Beetle for a friend. I was given photos of it as a reference. It was a gloss kind of mint color. I am about 60% through and got to the body coat... I searched and searched and the only thing I could find reasonably close was Tamiya Color PS-54 (I hate spray cans, I try to use my airbrush whenever possible). I sprayed the body inside and out and it is as I feared, just too dark. The model owner will understand and not bark, but I would like to try something. Is there any kind of trick to lighten up a coat like that?

 

Also, some of the coat on the top of the body (roof) is a little grainy. What is the best bet to smooth that out? Sand and respray? Or just spray over it?

 

Thanks.