How can I avoid failing with gray hair dye shampoo?

A photo from my university alumni gathering was posted in our group chat yesterday, and I was shocked because I looked so much older than everyone else.

I don't know how everyone else manages their appearance.

We are clearly the same age, but I looked like a grandmother.

The gray hairs along my part stood out particularly in the photo, so I felt depressed the whole time I was looking at it.

So I'm thinking of trying gray hair dye shampoo, but I don't know which one to buy to avoid failure.

I've given up on regular hair dye now.

After I used it last month, the top of my head turned bright red and even started oozing fluid.

I couldn't even tie my hair up for a week.

I heard that gray hair dye shampoo is milder than that, but I'm not sure if that's really true.

There are so many different types of gray hair dye shampoos, you know.

The prices vary wildly, and the reviews are all over the place, so I don't know what to trust.

I have a lot of gray hair behind my ears and in my bangs, so the gray hair dye shampoo needs to have good coverage. I really want to get my hair in shape before the next meeting.

Please let me know if there is a foolproof gray hair dye shampoo.

I want to look a bit younger in my next photo, too!