​How to balance colloquialism in the narrative voice?

I’m currently working on a western short story, and I was wondering how I could write the narrative voice? Character dialogue as of now contains a lot of colloquialism (y’all, ain’t, ‘in instead of -ing)… but I feel like having the narrator speak like that in first person would be a bit weird and redundant. I also struggled with this same issue while writing a pirate story… any help would be appreciated! If y’all also have any advice for writing westerns in general, I’d appreciate it.