Help with flex container

Hey guys I need some help on a flexbox layout im working on. I currently have it set up how I want, however the third column (blue) is not actually a flex container. I ran into a problem with it expanding too big when I increased the size of the text. This worked to visually express the layout I want but I will need that right (blue) side section to actually be a flex container (but stay same size), so I can give it a different color than the background.

I changed the font size so you can see how the layout will look for the most part without having to make it full screen. I still just cant figure out how to turn that blue section into the same size container.

Hey, did you get the result that you wanted? I wanted to give you a solution yesterday but the forum wouldn’t let me post. It seems like you’ve made some changes.