Here's a different approach you might want to try. Your data is currently in a "wide" format meaning every temperature tag is its own column. Try "stacking" it into a tall format.
Go to Table -> Stack, to transform it into a "Tall" dataset with only one temperature column, and a new "Label" column which specifies which tag each temperature reading came from. Next, use Rows -> Color or Mark by Column and select your Label column. From now on, the default color in Graph Builder will be determined by the value of that row in the Label column.
Finally, plot it in Graph Builder using Label in the Overlay role.