How to make the heart of the health gauge blue after eating an item

I'm making a mod that will allow you to eat diamonds now. Now you can eat diamonds. When I eat diamonds, I want to change the color of my heart to blue for 15 seconds, but I have no idea what to do. If anyone knows the solution, please let me know.

(I'm Japanese. It's very difficult to get knowledge of modding in Japan, so I thought I'd ask a question on Reddit. However, because I can't speak English, I wrote sentences using Google translation, so it's very difficult to read. I think, but please forgive me.)