I have been travelling a lot at night recently and have noticed 3 distinced colors of streetlighting The least common is the bright white mercury vapor lights used on a couple of public sports grounds the second are streetlamp!PS used on the main roads here they appear as a light copper color when fully warmed they are almost white but still have a copper tinge to them the second type are the ones used in the side streets and sometimes for private use like factory yards car parks etc these have a deeper copper color and are more pleasing too look at. My question is what's makes the different colors as far as I know both sorts are HPS is it diffent gas mixtures or some other difference?

On the different colors: maybe sodium dosed too low? And MV in use on sports fields? It's all MH here.

"Light copper color but still white" sounds to me like warm white ceramic metal halide, which I have seen some larger municipalities like Chicago relamp HPS fixtures with CDM lamps when the HPS lamps go EOL.

Also the bright white lamps you see lighting sports fields and such are most likely metal halide, not mercury vapor. Ive only seen one sports installation with 1Kw DX mercury vapor, but nearly 99% of such applications use quartz metal halide, typical wattages being 1000w and 1500w

"Deeper copper color" most likely HPS. Some say "amber" or "yellow" I personally think HPS looks more orange than yellow.

i see this color also in Italy, they are all metal halide.

The correct reference of the color of regular HPS lamps, is golden orange. High xenon pressure HPS lamps, have more clean and saturated golden orange color than regular HPS lamps. I've yet to see mercury free HPS lamps in person.
My Sylvania HSI-TD 70W/D, have a white light with slightly yellowish tinge, thats slightly reminds the color of american probe-start MH lamps, but the kelvin is higher. It isn't looks like a real bluish white light my Philips Tornado 23W 865 color helical CFL.
I like the reddish color of some old regular HPS lamps. Usually I expects for lamps with this color to begin to cycle after a while, but I've seen in Kiryat Ata, one AEG Koffer 150 at Zebulun street, and one AEG Triangel at the beginning of Shteinberg street, with their redded out HPS lamps stopped working completely without any cycles. With the AEG Koffer 150, the lamp was probably really EOL without cycling at all despite its conditions, which it should began to cycle. With the AEG Triangel, I also think that someone turned the lantern off.
There is a redded out HPS lamp at Zebulun/Shivat Tziyon, which during its cycles, have a dim orange glow that disappears and after some period of darkness, a bluish glow begin to gradually fade in, until the lamp restrikes with a bluish color.

Thanks I stand corrected on the sportfield lights I really thought they were mercury you learn something everyday! I had no idea that there was probably 2 completely different types of lamp in our streetlights I know that the ones in the side streets start off dull white when cold and gradually turn that nice copper/orange color as they warm up I must pay attention to the ones on the main road when they are first on and see how they behave. Though not just yet its bitterly cold outside at the moment