Hello laser, I can’t really tell what is happening in your case without a screenshot, but there is mainly a combination of the base color, the environment and the roughness (especially with metal).
Here I have a base color of 0.5, meaning that 50% of the light will be reflected and the rest will be absorbed by the metal.

As you can see, the background color is being darkened in the metal, while only half of the light is being reflected.
Usually metals reflect around 90 – 95% of the light, meaning your RGB values (of the base color) should be around 0.9 or so.
The shininess of the metal depends on the roughness, the higher the roughness, the less shiny it will be.
Even if you don’t understand this completely, thjnk logically: if your material is too dark, make it lighter.
And remember that metal is highly affected by the environment and lighting.