The entire SE Network is going through some redesign this year. TL;DR: giving each site a really nicely-tuned theme (color scheme, iconography, artwork) wasn't a sustainable model. This greatly slowed down some navigation redesign that's rolling out, and made adding features and fixing bugs across the network a nightmare for the devs, so themes are being stripped down.
The first group of redesigns just went live. There's your chance to see what level of differentiation is still being preserved and what the new left-navigation menus will look like. And imagine how much of RPGSE's design will persist or not.
If you have questions, concerns, or suggestions about what's coming I strongly suggest you read up on the network-wide meta Q&As linked above (and further linked from those) and comment/answer there. We--local elected moderators--have no influence on this process beyond what any meta.SE poster would. (Many of you greatly out-rep me on meta.SE, for instance!) I'm only posting here in hopes of making the upcoming change less of a surprise to RPGSE users who may not follow meta.SE activity.
Lastly, I would like to take a point of privilege to thank Jin for the work they did assembling this awesome design in the first instance. Thank you, Jin!!!