SFC/OP is still my favorite trek game to date, I don't recall a magnetic pulse??

It's basically a purple blob in the unremastered episode.
Back then the Klingons had now ship model, they received it in the third season.
You can see the Enterprise with this weapon here:

http://www.youtube.com/watch?v=tjCNeDJr5Bs

It's at 1:18 and Kirk calls the shots "magnetic pulses".
They became blue in the Remastered edition but nothing else changes.
This is also the only episode they are metioned in.

As for the arc in Star Trek 3 (and 5) : It was not really an arc, more like a green ball.

http://services.tos.net/pics/st5/st5-kli3.jpg

Personally I always figured it was a very small Plasma Torpedo launcher.
Interesting is also that is looks almost exactly like the Type F Plasma launchers from SFC.
This would also fit well with the original backstory that the ship was stolen from the
Romulans.
Additionally the weapon in ST3 looks nothing like the one the BoP in Star Trek 6 used, so
it can't be a photon.

Of course the idea that the Klingons used some other kind of torpedo in the Origninal Series was pretty much overruled by "Enterprise" where the Klingons were supposed to have Photon Torpedoes.
However Hoshi actually made a mistake since she said pu'Dah dak cha, which is made from the words phaser, something in the middle, and torpedo.
Actually otlh cha means Photon torpedo.
I do NOT speak Klingon, but I know that much.
So either it is a weapon different from our familiar Photons or it is simply a different name for them.
I mean a Photon Torpedo uses matter and antimatter seperated from another by *drumrolls* a magnetic field.
I must admit I would the Klingons to have a torpedo weapon of their own.
Of course everyone can use everyones weapons if he pleases, but the Feds have Photons and Quantums, the Romulans have Photons and Plasmas and the Klingons...?
I very much liked the idea from Microprose's "Birth of the Federation" where the Federation had Photons on the earlier and Quantums on the later ships, and the Klingons upgraded from Photons to Ion-Torpedoes.
Perhaps something like that as a modern successor would be quite nice.
Take a look at what the (K'Vort=supersized) Bird of Prey fires at around 4 minutes into the vid, does it look like your average Photon Torpedo?

http://www.youtube.com/watch?v=T8cMV...eature=related

They did not simply copy the Torpedo effect from the Enterprise D and turned it green or something.
It looks a lot different from other torps.
I'm all for a new type of torpedo for/from the Klingons.

it looked like that one round of torpedoes a little half way through the ep was a light bluish or purplish color when fired then slowly changed to a light green before impact..

umm, blueish?
Were you at right the timeindex?

The one at 4:03 is the one I was talking about.

The one at 6:10, which is blue, is NOT a torpedo.
The dialogue in the episode also clearly identifies it as a disruptor.

I was under the impression that a photon was a lightwave/particle and could therefore be any color, depending on its vibratory frequency.

right after the enterptrise flys off, and worf is ordered to fire

He's using photon as short for photon torpedo. He's not referring to the elementary unit of light.