Enamel paints

So my house currently has had trims and doors painted in Dulux Aguanamel in a bid to beat yellowing of standard oil based enamel paints.

Ive tried repainting a couple of my barndoors in Black aquanamel gloss but really dont like the finish. The gloss barely has any gloss sheen to it. Ive sprayed the finish too.

is the yellowing on oil based black enamel visible or does the black counter the visible yellowing?

Conversely, can someone give me some tips on spraying aquanamel paint to a smoother finish?


Cheers