cv joint

I just bought this stuff thinking it would be grey in colour but it's brown. Can i use this to pack the birf and housing? Has anyone used this before? Does the colour matter?

I've had my CVC joints replaced and a mechanic go through looking for what is causing a popping sound coming from the front driver side. They cant find anything that looks wrong underneath, what could I be missing? The noise is mainly occurring when turning and if I come off the gas the noise...