The first interdimensional tunnel that we first seen had appeared in "The Pilot" episode. Quinn was pulled into the portal and seemed to be turned into particles and transported through the interdimension until he reached the other side and was turned back to his original state and then he was thrown outside of the vortex to a parallel universe.
Usually we have seen the inside of the vortex in every episode, before the sliders enter the world, or right after they enter the vortex.
The last time we have seen this particular looking interdimension was in the season 2 season finale episode "Invasion" with the Kromaggs. In Season 3 it changed.
Not just a *minor* change to the inside of the vortex. This first alteration was a major overhaul to the look and feel of sliding through an interdimensional gateway or tunnel. Instead of the original inside that had a blocky feel and noticable particles flying forward we have now been introduced to a more *slim* inside. This tunnel seems to continue the pattern of what we see on the outside. The silver outside continues to filter on the inside and leads the way to the other side.
Why the change? Budget...producers decisions...but I feel there can be a more elaborate explanation.
Since the Sliders(Quinn,Wade,Rembrant, and Arturo) started sliding back in 1995 there have been since not very many skliders that we know of except for Smart Quinn who began only three months before our Sliders, and the people exiled from Kromagg Prime, but other than those people sliding has just begun. My theory is that ever since 1995 more and more sliders started journeying to parallel universes...for instance all of the other Quinns, Wades, Arturos, and Rembrants. And it wasn't until sometime in 1995 or 1996 that the Kromaggs began sliding to other worlds to conquer them using Manta ships which take up an awful lot of space inside the wormhole. I have come to this conclusion--the more people that slide and take up space inside the interdimension seem to have a great side-effect or reaction to it...I believe that the more people that enter cause the wormhole to collapse a little or disintegrate...straining the wormhole making it harder and harder to withhold the link between universes, this would cause the interdimension to change in shape, color and ability.
Yet again in the season 4 premiere episode "Genesis" we saw another new looking interdimension. This was a result of the transition of Sliders from the FOX channel to the Scifi channel. But once again I have come up with a solution...or explanation.
This seasons interdimension looks nothing like last seasons...a silver stream pathway that turns around circular angles to the other side. Instead however...I think this seasons is an actual improvement over the last one. This seasons Vortex is one of the causes of the interdimension change.
During the fight with Rickman in the last season 3 episode the timer had become damaged...resulting a weaker vortex. The vortex instead of silver has become blue. The inside a blend of blue and green...looking like a waterfall zooming from one point in space to another. This change could be a result in the timer damage and vortex alteration but I think that this further concludes my theory that the interdimension is collapsing, becoming weaker. In season 3 more sliders have been travelling to parallel universe...like Logan St.Claire, 150 survivors from Maggies homeworld, and Rickman who has been sliding for months. I believe that this is degrading the interdimension. It could result in the collapse of the entire universe if this continues.