How can I create colored boxes / containers?

Question

Self-answered and possibly duplicate. Please see first answer <3

title is so freaking dumb that please someone fix or suggest me an alternative title.

What I want is basically this:

With https://ctan.org/pkg/tcolorbox I only managed to achieve one singular box that I could split in half with horizontally but that is it. I can't replicate a color box like this, even a black/white one. I don't know if I understand this correctly:

If yes or not, how can I make a layout like this?

My furthest attempt:

\documentclass{article}
\usepackage[most]{tcolorbox}
\usepackage{lipsum}  
\usepackage{bookmark}
\newtcolorbox[auto counter,number within=section]{theorem}[1]{
    title={\textbf{Theorem~\thetcbcounter: #1}},
    bookmark={#1}
}
\begin{document}
\section{example box}
\begin{theorem}{example theorem}
  \lipsum[1]
  \tcbsubtitle{example theorem cont.}
  \lipsum[2]
\end{theorem}
\end{document}

which is. literally nothing.

which summarizes my latex skills. help :(

This is not for commercial or any serious book writing I just want my notes look kinda shiny.

Answer 1

Turns out to be duplicate of How create these boxes style?, already provides a customizable entrypoint for my problem. Thank you all anyways!