Here is a job you might want to tackle over the winter. As the majority of plastic resin 'enamel' badges seem to be losing their colour infill, so here is a way to get something more permanent.
This involves melting the remaining resin out of the metal and it will burn, so do this OUTSIDE with a blow lamp or camping stove. Hold the badge face down over the flame with pliers until the resin drops out or burns off. (See pic below)
When cool, give the chrome a good clean and degrease. Using a small artists brush fill in the relevant parts with enamel paint, i used Plastikote. Try to float in the paint rather than brushing it and it will find its own level. Don't worry if you get a little paint on the raised areas, there is no way you can easily paint around such small text using this sort of paint so don't try too hard as this can be carefully removed with a matchstick or small craft knife blade when paint is still soft after an hour or so. Just needs a steady hand to clean up the small raised text
When the paint is fully dry you can buff up the raised chrome areas. Don't use anything too abrasive on the chrome.
After a couple of days, to ensure the paint is protected apply a coat of 2 pack resin varnish (this is available on ebay and is used for varnishing fishing rod whippings, does not discolour and is very tough). So it can go over the chrome on the smaller areas. This stuff is not easy to thin out so try to do it in one go and reckon to throw the brush away.
I chose to colour up the anniversary badge even though i like the design of the black original i wanted to see how the colours lasted and also to match my other badges a bit. The badge has been on about year now with no sign of fading or dropping out, got to be better than the original materials used. Bonnet logo (newer plastic enamel) ones should be much easier to do than the anniversary badge as there is no small text to clean up, but at worst if you mess up too much you can remove the enamel paint with white spirit if it is wet or paint stripper if dry. Then try again. Have Fun...
I found on my cowl & "boot" badges that the plastic just came out easily with a sharp hook or an awl. Then cocktail stick with car coloured paint on it floated in. Looks good - come & have a look on the MSCC stand at the NEC.