I have APC 3157 superwhites all around on my vehicle right now, but I want to switch over to pure yellow bulbs (yes, there is a difference between amber/orange and yellow) and the only styles they're currently made in are 1157/56 and 168. I'm wondering if anyone knows of aftermarket sockets made that allow you to convert 3157 to 1157, 3157 to 168, etc?

I have looked around a bit and have not seen any conversions.
I thought APC made all there colors in both bulb base styles.
Did you try autosyndicate?

I've looked everywhere for them, APC only makes 3157's in Red, Green, Orange, Blue, Superwhite and Purple. They do make 1156/7 bulbs in yellow though, not sure why they don't make 3157's that way. Would be nice to get it swapped because everyone has superwhites nowadays, and besides orange and white, yellow is the only other color that's legal for upfront. Can't imagine I'd last too long with purple turn signals :).