Help required

This is a random posting seeking advice from all you good artists.
I'm hoping that someone has experience with painting on wood. Let me explain one of my hobbies is making small musical instruments for example mandolins.
I would like to make use of pyrography to decorate various surfaces and combine this with highlights of paint. I have included below and example of the type of thing which when I master the technique with the hot iron could be used.
What I am asking is has anyone got experience of using paints in this way on this surface my reason is that the paint has to be durable it will probable sit under a varnish but I would not want it pealing off in the future. In the example below I have used some acrylic paint which was used straight from the tube no thinning, would this be a good idea or should it be diluted down and if so what would be best to thin it with other than water. As you can see the colour as applied looks flat and lifeless.
Any assistance or comments would be most appreciated.
I know this is not digital art however my link is that I use the computer to first work up an image I intend to use. My normal work is with inlay materials such as Mother of Perl, Abalone or veneers.
If this is in the wrong place please move it or get rid of it for me.

I've moved it to the traditional media section as it seemed better placed there.

I have painted on wood with acrylics before and I believe I used Daler Rowney System 3 paints straight from the tube (maybe watered slightly to make them easier to paint with). It was actually for a house name sign to hang on the front gate so it needed to be fade resistant, so I covered it with some generic UV resistant varnish spray. It lasted a few years and the colour remained pretty vibrant, probably would have lasted even longer if it had been regularly treated with a fresh varnish every so often to protect it from the elements.

EDIT - I guess the type of wood will also have an impact as some will soak up paint more than others.

Don't know if that helps.

Of course you can ask about traditional media, here! Not sure if the rest of us can answer, though I suspect a diluted paint will be less likely to flake and perhaps also look more "alive", but I really have no knowledge on the matter. I'd love to see some images of the work you have done already though, mandolins as well as inlays!

EDIT: I thought it was a bit odd to post this in traditional media and ask if it was the right place even though it wasn't digital.... Didn't realise Banj had moved the post already

I mess about with acrylics although I've never painted on wood (so feel free to ignore my advice ) and like Banj I use System 3 along with some other cheaper craft stuff.
One thing I frequently encounter is that even when used thick the paints are not necessarily as opaque as I want them to be and so here, the colour of the underlying wood may be dulling the colours (a bit like using watercolour on toned paper, but to a lesser extent.)
It might look more vibrant if you first painted the coloured bits with either thick, heavy body white, or a couple of coats of gesso, and then when it's all dry lay in your colours on top of that.

And if you want to thin it make sure you use a medium because too much water dilutes the binder as well as the pigment leading to possible flaking.

Val's advice sounds better than mine

Many thanks all I will carry on trying and keep you updated never expected responses so quickly.
Bj thanks for putting it in the correct place.