An old USN-issue sewing kit:
Note the colors of the threads: Navy blue, white and khaki. Those were enough to mend all of the uniforms that were worn back in the day.
I don't know if the Navy still issues sewing kits and if there are threads compatible with the new camo uniforms or the now-discontinued aquaflage.
As to why a sea-based service needs to wear camouflage uniforms, well, I've blogged about that.
New Year, New Things
6 hours ago