Why, you ask?
Because the costume colors signify a crewmans role on their particular ship, and the color scheme changed betweenTOSandTNG.
The same was true of the uniforms, as demonstrated by the luscious green shirt that Kirk sometimes sported.
In particular, Roddenberry brought back his original series costume designer William Ware Theiss.
And with it, he brought back Theiss.
For the most part, Theiss succeeded where Roddenberry and Fletcher failed inTMP.
TheTNGuniforms feel like 80s versions of the 60s original, especially after they were revised in season 3.
However, with the emphasis on division colors came a confusing switch.
Once again, science officers and doctors wore blue, but command now wore red while operations wore gold.
Also, theres the skant, but onlyLower Deckstalks about that now.
So why did the colors change?
So in the eyes of casual fans, the Captain wore red.
And even Trekkies had seen enough of Kirk in red that the idea didnt seem outlandish.
TheTrekuniforms have been altered many times since.TNGandDeep Space Ninelater limited colors to the shoulders, a look continued inVoyager.
These stories adhere to the division colors fromTNG, but whenever the franchise goes back to pre-TNGera including theJ.J.
Abramsreboot movies orStrange New Worlds theTOScolors come back into play.
And as long as some unnamed operations ensign gets killed now and again, thats just fine.
