I use the frag disks and plugs from here: http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=BA-FD&Category_Code=coralfrag">http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=BA-FD&Category_Code=coralfrag</a>
The plugs (haven't looked at the discs but I assume they are the same) are gray colored and not obnoxious white like others I have seen.
They have both discs and plugs. I have ordered from them numerous times. They are my favorite non-local fish supply vendor.