This may not directly answer your question but I believe you’ll find most of these answers by simply searching these forums as well as searching the markup language Discourse utilizes.
# This would be H1
## This would be H2
### This would be H3
As far as color styling, that is not inherently supported. However, you can get a plugin that does just what you’re looking for. Now I was going to link you the bb color code plugin we’re using but that doesn’t appear to be available (as a topic) on here anymore. So I’d say, check out this newer bb codes plugin. That would look like as follows:
I usually quickly pull up this list of web safe colors and use the chart at the top.
P.S. - Generally the ideology of Discourse is ‘keep it clean and simple’, which I like. However, there are times where you’re looking for added functionality not provided. This is where plugins come in handy. Therefore, I’d recommend you check out what plugins are available. If a plugin doesn’t exist for something you’d like, you could even ask if someone is willing to invest time into making it possible.