Hey Sam, not sure what DeVilbiss you have, but 40-50 isn't that much pressure. I usually shoot things around 35 to 45. Metalics sometimes higher to fog them in. It should lay down better at the higher PSI depending on what you are shooting, viscosity, and volume you are putting down. If you are shooting Rusto, Wood will have a "engineered formula"......its almost football season so I have to start poking and prodding him!
The white looks nice!