Any difference in red or black energy suspension bushings

[rs74]

I am going to replace the leaf spring and shackle bushings in my C10. I thought I read somewhere that the black had some sort of built in lubricant. Is this true? Or is it just a preference if someone want red or black. This is the last thing I am waiting on so I can get my order in to Summit. Okay here is the link that says the black bushings have graphite impregnated in to them.
http://www.sfxperformance.com/parts/...Suspension.asp