the repro-antique bodgers approach might be useful. get hold of some watercolour paint, even a kids poster paint set will do, and mix a really watery wash of a colour that makes up the difference - trial and error helps here, put some on and if its too brown or too yellow wipe it off and adjust the mix. make sure that its watery, with just a drip of pva in it, so that you need to apply a couple of coats to build up the colour (that way you can blur the edges so they arent so noticeable). I imagine that raw umber, and burnt umber are the colours you will need, perhaps a bit of white and a creamy yellow.
if the white patches are from where the wood hasn't been exposed to light, say under some removed beading, then the colours will even out anyway, but this paint trick will not be too extreme to cover the difference while you are waiting.
There are some ways of adjusting the colours of woods such as oak using potassium Bichromate, (an oxidising agent that ages the wood really quickly) or a vapour bath of vinegar and iron (put a cup of vinegar with some nails in it inside a polythene shroud over the wood for a few days. these are both fairly specialised tricks that are a bit over the top for your problem, I've mentioned them in case you want to try searching for the techniques.
