Re: gel coat Nr. SM 2005
Craig Briggs SN 68 Sangaris
I'm not aware of a gelcoat color number scheme and after many years of sun you may not get a perfect match even if you had the original factory color.
However you can easily get an excellent match yourself. Here's a link to an excellent DIY site called Boatworks.com. He covers all aspects of repairs, but this link is specifically on how to match colors. https://www.boatworkstoday.com/?s=color+matching
I followed his technique and unless I point the repair out, you really can't see it. At 6 knots on a dark night it's even better :-)