Jezbowman, the standard light marking for a holding point uses amber coloured lights. There could be one or two on each side of the taxiway or a couple/few of them make a short bar across the centreline of the taxiway.
If the taxiway uses blue sideline lighting then it will usually be easier & cheaper for the airport owner to use amber sideline lights ie replace a blue light on each side with an amber one abeam the holding point. If green centreline lights are used then amber lights - often three of them in a short crossbar arrangement - replacing a green light at the holding point is usually easiest & cheapest.