Probably pics out there. They had them as jeans in the late 1960s, when I was visiting a warship.
[UPDATED TO ADD]
Looks like they used to be jeans: https://nara.getarchive.net/media/right-enlisted-dungaree-un...
Now they wear Navy camo as work uniforms: https://www.mynavyhr.navy.mil/References/US-Navy-Uniforms/Un...