Something I did almost 12 years ago.
In the case of Geordi, Picard, Riker, and Data, the colors were grabbed from TOS. Picard is captain, so he gets the Kirk wraparound color. Data is in science division. Command and operations colors are as they were for TOS.
Security is brown, both to distinguish it from engineering and to make it resemble the command gold/avocado a bit more (as fanwank to mesh with the Franz Joseph Technical Manual's inclusion of security topics in the command section; also there's a tight relationship between security and command, e.g. as is a plot point in "Turnabout Intruder"). Brown is also a bit less conspicuous than bright red, at least to humans.
I've forgotten now whose colors I tweaked in medical, Beverly, Troi, or both, but the idea there was to make it look good, keep them close to their TNG colors, and give them the
same color, to justify Troi's dress as a casual uniform for interaction with the civilians aboard. So, Beverly and Troi are both in the medical department, and its colors are distinguished from science. What the heck is the medical color? People can argue about its name; it's something close to
mint.
Wesley is in a cadet uniform.
So, I've separated medical from science and security from operations, for (at least) five divisions.
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Here are a couple of concepts from the TMP era, "fixing" the science orange.
