A student shared this paper by Blakeway and colleagues. It shows the leads of the heart color-coded by region. It’s awesome. I’m posting it here mostly so I can find it again. Link to the PDF, look at the figure on Page 2: https://www.resuscitationjournal.com/article/S0300-9572(12)00053-6/pdf

Citation: Blakeway E, Jabbour RJ, Baksi J, Peters NS, Touquet R. ECGs: colour-coding for initial training. Resuscitation. 2012 May;83(5):e115-6. doi: 10.1016/j.resuscitation.2012.01.034. Epub 2012 Feb 2. PMID: 22306667. https://pubmed.ncbi.nlm.nih.gov/22306667/