Where are you located? For many of us it’s autumn and deciduous leaves are getting ratty. I honestly wouldn't worry if that’s true for you. Those leaves will be gone soon. Next year’s buds look fine.

agree with everything flora said ... big city name good enough.. and how about a pic of the whole plant ...

and the buds are the future.. focus on those.. and they look.. as flora noted fat and happy and ready for next spring ...

ken

There are some hydrangeas that can develop yellow variegation due to leaf pest damage or the introduction of viruses into the plant (some may become well selling cultivars while others have to be destroyed). Unfortunately, at this time of the year, yellowing may also be caused by dormancy so just keep an eye on the leaves.

A virus infected plant can develop many types of variegation that would be present at other times of the year too. Macrophylla varieties seem to be the most attacked. Some symptoms: mottled leaves, chlorosis, blisters, rings, distortion, less vigor and stunting.

Dormancy induced yellowing would normally occur near the end of the growing season or in periods of lots of extremely cloudy weather. Yellowing caused by dormancy would increase with the passage of time, covering the whole leaf in typically the same shade of yellow unless there are other leaf issues. Feel free to dispose of the leaves in the trash when they drop.

Thanks all here is a picture of the whole plant. I noticed whitish small bugs on back of the leaves

And I live in San Francisco

Not sure if the bug is visible for you folks in this picture

Are these aphids?

Could be but it was too small for me. Take a sample in a sealed, transparent bag to your local plant nurseries.