Yes, this is a known issue. Please do a search for other threads.
I think the only solution was to go back in and fix the HTML or try again. Usually I clear the formatting or redo it a couple of times and it works.
The spacing may be a glitch, however, the color may be set on the template level, which is why it’s giving you trouble changing it. Ask the person to confirm whether the color is hard coded into the template and what kind of text they’re trying to change (add to calendar is a whole other problem which must be given a calendar class on the template and then in the HTML a calendar tag must be used. This could just be Marketo being finicky.