Dual Phase Sabers

[Starkindler (The Naked Jedi)]

As I understand it Dual Phase Sabers have two (or more) distinct lengths. Each length requires a different focusing crystal which is either engaged or disengaged by use of an external knob which moves the new crystal into place amidst the beam.
The main crystal (Adegan) is fixed in place as it generates and sustains the blade. Making a saber that had swappable main crystals seems untenable due to their generally larger size and the space constraints inside the hilt. The Focusing crystals are the ones that can be made moveable.

[Shatir Lavan]

It depends entirely on the colour of the second crystal. Vader had multiple red crystals so even though his blade could change length, it was always the same colour. Corran Horn had 2 different colour crystals so his sabre changed between green and coruscating.

[Starkindler (The Naked Jedi)]

perhaps just basic color theory.......Crystal One is blue, crystal two is clear + normal length blade.
Crystal ONE is Blue crystal three is red = purple other length blade??

[Starkindler (The Naked Jedi)]

from what I've read those are the two most common crystal colors among the Adegans (which are supposed to be hard to find).

[jedi12]

The Length of a dual phase saber cannot be done but the color change part can my freind and I are in the proccess of doing it

[tanzanlinnear]

According to the Good Lightsaber Guide I found, there are only two natural Adegan colors, Blue and Green. Purple blades are the result of a blue crystal being alchemically treated, much like the Sith artificially create their own crystals.

[jedi12]

my character Jaryk Lyghtsyder will have a color change lightsaber soon. that I will have one a freind and are in the process of making one it will change from silver to purple like corrin horns