Hi all.
I've created a little add-on to Squarewebsite's brilliant "Squarespace Custom Table Block Plugin".
It let's you customise the colour and font size of the "ticks and crosses" that are fed through from the plugin (default is green and red).
Just copy and past it into the "footer" section of the "code injection" settings.
(I've added it as a text file so your browsers don't think it's malicious)
Ta!