Give me a couple of days I have a yellow one. I have somewhere the original muffler guard that has been broken. If I can find it I could cut off and send a piece. I don't think taking a pic would help,cameras and monitors being an unknown in the mix. I had a guy back in the 90's match that yellow exactly,so I painted a nos guard and replaced the old one.
I'm guessing by your white reference you have a K2? The one with the rear foot brake,long rear fender and the oval tank badges? It was called Mexican Yellow. It might be best to start a new thread so others will see it,someone must have matched it by now.
If you look at my post needing help with my tailight bracket you can see the color I painted mine. If you or anyone else likes the color, I can post a picture of the paint name and code that I used. Let me know