That thing is the difficulty of being able to clearly see the boundaries of my chat windows against a black background such as the solar system map (which is displayed frequently when I am probing or otherwise examining a solar system) or the blackness of space. Here's an example:
Keep in mind that I often have a lot more unstacked windows open than what you see here. I can't tell you how often since this patch that I have accidentally closed private convos or other windows because I couldn't easily see what I was clicking on. It is beyond irritating. Prior to Rhea, I could create a custom color scheme that allowed me to meaningfully set the color and transparency of windows so that their boundaries were easily visible. That is no longer an option. Instead we are given a bunch of so-called color themes that are *barely* distinguishable from one another. The new transparency slider makes zero difference against a black backdrop as shown above.
The worst element of the new design is that the boundaries and backgrounds of all in-game windows except the currently selected one are black--except for a few that have have barely discernible faint highlights on the top and bottom edges. For example, my Drones window has these faint highlights but not the Selected Item window. Furthermore, the bounding lines of all windows including the currently selected one are so thin and faint that they are extremely difficult to see. These two issues combine to create a huge amount of visual confusion when I have a bunch of in-game windows open and overlapping each other in random positions. I'm pretty sure it's not just my 56-year old eyes being the problem. It is very simply thoughtless and terrible user interface design.
In case you're wondering, I play Eve on Windows running in a Parallels virtual machine on my iMac 27" with 16 GB RAM and NVIDIA GeForce GTX 780M 4096 MB graphics card. It is perfectly capable of running Eve on high quality. Here are the graphics and general settings at the time the screen shot above was taken:
The Sisters of Eve theme is the lightest option available and even it sucks. I am fucking frustrated at no longer having sufficient control over my in-game settings to make the goddam game windows easily seeable. FFS, these windows are central to being able to play the fucking game! How can I play if I can't easily see and manage them? *RAAAAAGE*
I hope that Eve's UI designers come to their senses and give us back some control over how we can configure the in-game windows' colors, or at least the contrast. It's design hubris in the extreme for them to impose their own ideas of color and contrast choices when individual players have such widely varying visual challenges and preferences. There is no good design reason in the world to not AT LEAST permit players to adjust the contrast in their own game client, and at best allow color and transparency customization as was possible before.
And hey, if I am missing something obvious about how to make my in-game windows more visible and discernible from each other, then I'm all ears.