I almost completed my bougainvilleas puzzle

I have always been fascinated by this ornamental vines/bush/tree. I have huge bushes growing wildly in my yard of the magenta and purple colors. A while ago, whilst travelling I found some with orange and red flowers to add to my collection. I have looked and asked around quite avidly for a local supplier of white, pink and yellow. No one answered. This weekend I attended a wedding a while from here, and low and behold, at the supplied abode, there was pink and white growing on the porch!
Needless to say, some cuttings found their way to domed pots on my window sill.
Now all I still need is yellow. I don't know if I imagined it, I read somewhere that there is also a red and white colored one? Is it true? Can anybody perhaps help me obtain such seeds?

TIA

Yes, there is at least one multicolored Bougie, but no, it won't come true from seed.  I have B. 'Masquerade' and it blooms like a Japanese Quince, some flowers all white, some coral-pink, some half & half.  They all evolve to pink  as they age.  It has variegated foliage that is more salt & pepper mottled green on white, with some leaves all green.  The green is non an attractive shade and the white is not a clear white.  I've had this one since ~2000 and I've never seen it elsewhere.

There are many other variegated varieties:  I have Raspberry Ice with red flowers and Blueberry Ice with more purplish flowers.  R.I. has a lighter green than B.I., but both have clearer white parts.

Interesting.... I have seen a couple of other hybrids. Maybe if I have one growing well some day I will play around and graft other vines to make different color flowers come out of one tree (not my liking personally)..
I think the yellow and red/white one I still need are not hybrids. Same with the stock standard magenta, purple, pink, orange, red and white I now have. I am sure of the yellow, but not of the red/white. Wikipedia makes no mention of them. Probably a hybrid then. Thanks for helping with this.

You won't be happy with grafting different colors together.  They don't necessarily bloom at the same times.  This is common with Rose of Sharon advertised with multiple colors.  So half the the tree blooms and then later the other half blooms.  It looks stupid. Notice the shape and size of the Bougie leaves which tell the story that they are from different continents.