I'm under the impression that Worf's uniform change from gold to red was due to accepting the Strategic Operations Officer position aboard DS9 but I thought red was for those on the command track, not operations, and it would seem that coordinating "strategic operations" for Starfleet would be an operations position.
What about this particular position change prompted the uniform change? Or was there another reason for the change unrelated to his new job title?
You've mistaken "Operations" (those responsible for the conduct and good running of a ship or station) with "Strategic Operations" (those responsible for managing the disposition of fleets, ships and defence stuff).
Although the names are superficially similar, one is a Command role and the other is not.
The original screenplay from "Way of the Warrior" makes it abundantly clear that he's moved back into a Command-track role.
166 INT. OPS
Close on Worf, as he steps out of the turbolift. He's now wearing a Deep Space Nine jumpsuit in Command red, along with his usual sash.
...
O'BRIEN: You look good in red.
WORF: It feels good. But I have much to learn about Command.
O'BRIEN: (re: Sisko) Well, you couldn't ask for a better teacher.
You're right to infer that it's related to taking on a different role, that of Strategic Operations Officer (That is essentially spelt out in the transcript others have provided) and that that role falls under the Command division. As @Valorum points out, the mere fact that the position contains the word operations doesn't make it an Operations role.
The word you should be concentrating is strategic. In some respects strategy is the defining feature of what Command does.
From Wikipedia:
The terms tactic and strategy are often confused: tactics are the actual means used to gain an objective, while strategy is the overall campaign plan, which may involve complex operational patterns, activity, and decision-making that govern tactical execution.
That is not run of the mill Operations which essentially means the branch responsible for making things happen and keeping things running.
I would also note, the Operations in Strategic Operations may be in the sense of a military operation. In other words, he works on operations (actions) of a strategic kind (i.e. not strictly military). That may include actions of a Special Operations nature:
Special operations (S.O.) are military operations that are "special" or unconventional and carried out by dedicated special forces and other special operations forces units using unconventional methods and resources. Special operations may be performed independently of or in conjunction with, conventional military operations. The primary goal is to achieve a political or military objective where a conventional force requirement does not exist or might adversely affect the overall strategic outcome. Special operations are usually conducted in a low-profile manner that aims to achieve the advantages of speed, surprise, and violence of action against an unsuspecting target. Special ops are typically carried out with limited numbers of highly trained personnel that are adaptable, self-reliant and able to operate in all environments, and able to use unconventional combat skills and equipment. Special operations are usually implemented through specific, tailored intelligence.
In fact, on a number of occasions, we have specifically seen Worf involved in planning and executing special ops.
From the script when his post is announced:
Worf enters in red shouldered DS9 uniform and his sash)
WORF: Lieutenant Commander Worf reporting for duty.
SISKO: Well, you all know our new strategic operations officer.
SISKO: Assume your post, Mister Worf.
WORF: Yes, sir.
O'BRIEN: You look good in red.
WORF: It feels good. But I have a lot to learn about Command.
We can infer from the dialog that the strategic operations officer was considered a command position.
In Worf's job as strategic operations officer he coordinated all Starfleet activity within the sector. We see Worf doing several traditional command roles including:
It was a command position because he was coordinating activity a vast and strategically important area. You can see that he was regularly meeting with captains, admirals, and ambassadors in his role.
