How to add materials to individual objects inside of a block

If i have a structural element like this which is a block object, where the columns, the bolts and the steel inserts are all part of one block and the block is copied multiple times and I wanted to add a material only to the columns inside of the block, what is the best way of doing that, would I have to explode each block and add a material?

Nevermind, you can use block edit which I forgot about lol