I've tried colouring leds to look more like filament bulbs worked well enough on the larger (5mm) ones but the smaller ones (3mm) seem to have a bluish light to start with - still it should be possible, just hsve to experiment a bit more!
I did in fact buy a set of the xmas lights, (just in case I need some later when they no longer sell them), this is how they look compared to the leds...
could have a model railway use too!