By giving them a metallic value of 1. Materials with full metallic value will reflect whatever diffuse color you give.
I’m curious to know that without aid of a colored Specular how are we to achieve metals like Gold, Copper, or Bronze?
Anyone have any input on this?
Thanks Jacky! Gonna give that a shot now.
Worked perfectly, though iwth setting Metallic value to 1 my scene get’s significantly darker, any fix for that? 
EDIT: Resolved by giving a constant of 0 to Specular. Cheers again Jacky!
Hey ,
In addition to Jacky’s answer, you can check out Material_Nodes map in ContentExamples for a good representation that you can play around with. There is also some good documentation here: Unreal Engine Materials | Unreal Engine 5.2 Documentation
Hope that helps!
PBR is super easy when you are after realistic looks really. You don’t need specular value for metals(and you dont need it in general), but you need a roughness value for almost every kind of material.
Thank you very much ! PBR is definitely something I’m going to have to get used to, but I’m getting there