I want to use the css file to assign a color to each text nodes. I want each nodes to have a different color. To do so, I want to set a node id or class and assign a color directly from the css file. How can I assign an id or class (used in html) to the text node?
Have you examined the Editor using your browser's dev tools? That is always the place to start with issues like this. I should let you see how nodes are identified and whether there is any realistic way to change the css.
Where can I see brower's dev tools?
@TotallyInformation is refering to the built in devtools in your browser. You can use it to inspect and realtime change things to see what affect you can achieve
In most browsers, simply hit "F12" on your keyboard.
Here is a video of someone using devtools - he does a good job of showing you how you can use devtools to find and test CSS changes in realtime (to make sure it does what you want)