It does not only look good, but I would also harshly recommend that you mix warm and cool metals in the same room.
Let’s clear up the confusion of what is cool and what is warm metal:
Warm Metals: Gold, Copper, Rose Gold, Oil Rubbed Bronze, and Brass.
Cool Metals: Silver, Chrome, Nickel, Steel, and Pewter.
There are also neutral colored metals, which is like neutral colors. They work well with all the cool and warm colors:
Neutral Metals: Iron, Gun Metal, and other black metals.
How can you quickly decide which undertone will look best in the room?
Well, it depends on the feeling you wanted to add in that room.
For example, you have a cool color scheme in your room. Do you want to balance or accentuate the color temperature of that room?
You can confidently use cool metals to accentuate an already cool color scheme.
On the contrary, you can use brass or gold to balanced the cold feeling in that room.