Advice for re-painting

[Ethelred the Almost Ready]

I have started painting a large monster and had bought a new paint thinking it would work well with the figure. 
The creature is a metal Reaper figure with some greenstuff modifications, has been undercoated and I have started the first layer of paint.  Half way through I have decided I don't like the effect.
I don't want to strip the paint and it is only a thin coat. 
Am I best to repaint with the black undercoat or paint with normal black paint?
Anything else I should do?

[has.been]

You don't say how you normally paint, but my advice is to treat the mishap
as another 'thin' undercoat. Simply treat the figure as you normally would.
If you usually undercoat in:- Black; Grey; White or whatever then continue to do so.

[Cubs]

If it's already had an undercoat, I wouldn't put another on, no point. When this sort of thing happens to me, I paint over it with a thin layer of black and start again.

[Ethelred the Almost Ready]

You don't say how you normally paint, but my advice is to treat the mishap
as another 'thin' undercoat. Simply treat the figure as you normally would.
If you usually undercoat in:- Black; Grey; White or whatever then continue to do so.

How I normally paint is badly   

The current layer of paint is thin.  I will go with Cubs suggestion as that was my inclination.
Thanks

[has.been]

Having seen examples of Cub's painting, on this very forum,
I too would follow his suggestions.

[Orctrader]

When this sort of thing happens to me, I paint over it with a thin layer of black and start again.

Me too.  In fact, I often change stuff as I go along.  That said, I tend to paint with quite thinned colours anyway.

[ced1106]

If the current layer is suitable as an undercoat, then just paint over it. Otherwise, paint over the layer with an undercoat layer.

Note that I'm using the term undercoat *not* as a primer coat, but as a supporting color underneath another color (eg. brown under gold, or red paint under red metallic).