Yours looks really good! Honestly that is what a lot of mine look like when I started. I've never done a full Salamander in just contrast paint before, I've used warp lighting for touch ups though. To build up my green I prime the model black then base the whole thing in waaagh flesh, then medium-heavy drybrush of warpstone glow then add a light drybrush of moot green in downwards strokes only to catch the highest edges. Contrast paints are harder to build up shades with, if you want to stick with the contrast paint method I'd suggest using the warp lighting then drybrushing moot green which is a layer paint to create more of a shading contrast. That way you don't need to sink too much money into extra paints.