If you are looking for stock replacement, the best way is go to junk yard and pick some.
For needle, if it is SVT, the plastic is red orange color so you won't able to change it unless u custom made it.
I saw someone sell clear one. http://www.contour.org/ceg-vb/showthread.php?76350-Clear-Gauge-Needles&highlight=needle
However, the light source of the needle is the same light bulb as the back lighting.
For example you use a blue light bulb for the back lighting, the needle will be blue too(if you are using the clear needle).