Q.I Have A Yellow Hibiscus With Half Yellow Petals And Half Red Petals Is This Unusual
I notice that on the all yellow flowers the stem is all yellow but on this flower the stem is yellow and the ti is red

Certified GKH Gardening Expert
Your plant is a chimera! In most cases, this is a genetic mutation. In some, more rare, cases... This is a case of Siamese twins, or two different individuals residing in the same body.
If the problem goes away over time, then it is a simple genetic mutation. If this persists... Then you have really unique plant, that is actually two separate individuals!
https://www.gardeningknowhow.com/garden-how-to/info/what-is-plant-mutation.htm