Coloured dash bulbs on favorit

Have noticed these bulbs on ebay. Anyone tried them? Do they effectively simply change the colour as it would be bad if they were glaringly bright or went dull. I think my oil light is dead as it does not come on at any time so was considering swapping out all the bulbs if i took out the instrument panel so that i hopefully wouldn't need to go back in to change a bulb for a long while.