Currently, on meta sites (site-specific metas and MSE), the only difference between a normal tag and a moderator-only tag is the red text:
I have moderate colorblindness (specifically protanopia). To me, the moderator-only tags look almost identical to regular tags - the only difference I see is that the background is slightly darker. The text looks almost identical (I only know that the moderator-only tag text is red because of inspecting the color property in Chrome's developer console).
It would be great if the different types of tags could be more visually distinct, to make the site more accessible to colorblind users.
For reference, this is closer to what the above image looks like to me (with simulated colorblindness using this tool):