Need help with painting spots

[amrogers3]

Can't seem to be able to paint spots. If I thin my paint and use multiple layers, the spots look more natural but can't seem to exactly paint inside the spots every time and it looks thinner on some of the edges.
View attachment 61527
If I use paint straight out of bottle, the spots look crisp on edges but spots appear raised and it doesn't look natural.
View attachment 61528
I'm stuck.

 

[Chaotic Creations]

Thin paint option and then touch up with base colour once the spot colour is opaque.. or preferably (cause the yellow is going to take many layers to get opaque). Gradually build up the colour from a dark brown to yellow. Will give a realistic effect.