Had a quick look: it appears you can fix this with a local CSS file. Create a directory called /opt/rt5/local/static/RichText and in there copy the file `/opt/rt5/share/static/RichText/contents-dark.css``. Then edit the new local copy and change the hex colour value in the third line. So for example I have a nice red text with:
/* main input color */
.cke_editable {
color: #f70101 !important;
}
Flush your Mason cache, restart the web server and then take a look (you might need to shift-reload your web browser if it caches the CSS style sheet).
If you want a really Goth look, try this:
/* main input color */
.cke_editable {
color: #ededed;
background-color: #020202;
}
