Aluminum Oxide Grinding Wheel Color

[theminor]

I'm looking to replace the grinding wheel on my grinder with an aluminum oxide "white wheel" so I can better sharpen my HSS turning tools. I've seen some online for $15 or $20. Is there some significance to getting wheels that are actually white? I've seen others that are gray in color, but are made of Aluminum Oxide. BORG sells a wheel that is supposedly made of Aluminum Oxide but it is dark gray in color. Is there any difference other than the color? This guy here seems to think that the color does not matter (see number 10 in that link)

[Stytooner]

Buy only quality wheels. Once you determine that it is the material, size, grit, speed and price range you want, then you have to look no further.
Color is really of little significance. I have seen the very same thing from different makrs in many different colors.