Yellow is very new, and not at all dependable from seed. You can pretty much count on white and red.
Mr Ko, Adenium_ko, page two, plenty of seeds! look at page one, also. Remember, they might not look like the photo.
http://shop.ebay.com/adenium_k...
I would buy 40 or 50 seeds, of a mix, and cram them all in a kitty litter box. half and half perlite and peat. Drill LOTS of holes in the KL Box, on the bottom and sides. Need great air circulation.
Here's a yellow grafted plant for sale by Khwarunee: ($24.00)
http://cgi.ebay.com/ADENIUM-OB...
These two people are the ONLY two to buy from on Ebay, unless you stumble across Durham Botannical's occasional sales. Oh, and there's a fellow in Florida who has some large caudex plants, but his ebay store is a mess. confusing.
Here's a bloom that will be open when I get home this afternoon, I hope! From the same lot of seeds that made the yellow. There seems to be a bit of yellow inside....