My husband is 32, and has the problem of premature greying hair. Is there any Ayurvedic remedy for this?

Sorry but 32 is not prematurely grey. I look at it this way, it is better than the alternative which is male pattern baldness. I can’t recommend anything for you because I haven’t found anything that works except to color it when needed (and yes I get tired of doing that too) What makes matters worse is I have a beard and that shows the grey much faster than the top of my head, so I color my beard about once a week. Like I said though, I’m just happy I still have hair!