Samsung notes has a nice feature, where I can select a pen-modifier and a color, and when drawing over existing text, this text will change it's color to the selected color, which was set for the pen-modifier. It's quite similar to the Lasso-tool, to edit the color, but the lasso tool can be quite painful to use. Especially, if you have a big formula and want the change the color of specific letters in it. Then you would currently need to select every single letter anywhere in the formula, and then change it's color. With this new tool, I would just need to select the tool, the color, and when tapping/drawing over existing text, it would just change it's color.

Samsung notes has the ability, to change the thickness of existing text in the same way, but this is far less useful, then with colors.