When looking at your knowledge graph, oftentimes, you want to filter down from a top-down approach. Going from tag to note. While searching does solve this problem, it does so in a clunky and non-visual way.
Text labels for tags and notes are treated equally and show up at the same level of zoom. However, could a setting be introduced to make tags show up first. Because tags are far less common than notes, they could be shown at a more zoomed out position to provide greater context to the graph without adding too much visual clutter.
Creating different colors for each tag is a valid solution, but a clunky one. Requiring users to remember what each tag meant, can make it hard to “get back into” you graph when not using it for a longer period of time (I was currently on a ~4 week hiatus from Obsidian when I noticed this issue)