thermal paste mix grey and white

1) 'cause it looks fancy and they can make it more expensive
2) That's epoxy, don't use it on a CPU
3) Can't really tell unless you tell us the make and model of the paste so we can look it up or see if we've used it in the past. Please post details. The only two-part thermal product I see with a quick search is a thermal permanent adhesive.
 


thnx for answer me this its halnziye thermal grease hy 810 i can send a pic if you want
 
so apparently their customer service dont know what is the white syringe too..they told me its a present!!!!!!! and plz do NOT use it on cpu!!!! then why they included this in their product? its so funny
 
i don't think that's an epoxy - there are silicones that are two part (i work with some), and they describe that HY810 as a "thermally conductive silicone" on alibaba https://www.alibaba.com/product-detail/Halnziye-HY810-transistor-thermal-silicon-electrically_1874845445.html

Most silicones are thermally insulating, the only part of that that could make it applicable to cpu use is that it's something of an adhesive, but to be frank i would not use it

Carbon has the highest thermal conductivity, and there are diamond dust thermal pastes available - if you want the ultimate heat transfer, i'd go with one of those