What does the "they've gone to plaid" joke mean?

It's a play on the phrase, "They've gone to warp," from Star Trek, and the warp trail effect a ship causes when it goes to warp speed.

The ship has hit ludicrous speed, so they chose a "ludicrous color" such as plaid to represent that.

There's also an old Warner Bros. cartoon that uses this reference. There are 2 mice being chased by a hypochondriac cat. At one point, the smart mouse says, "He's turning pink!" The cat is frightened and turns pink. The mouse says, "He's turning blue!" The scared cat turns blue. The dumb mouse says, "He's turning ... plaid!" The cat suddenly gets kilt-colored and Scottish bagpipe music plays.

So it COULD be a reference to this cartoon. But I have no evidence.

It is very simple: If you move faster than light the stars appear as stripes. What would the next step after stripes be? Why plaid, of course....

It could be a reference to the astronomical phenomena of galaxies moving away from us at unbelievable speeds, they are said to be "redshifted." The light from the side moving away takes longer to reach us than the side moving towards us "blueshifted." The Doppler effect (sound) is similar. So I assume they needed a new color to describe just how fast Spaceball One was really going

If anyone has ever watched the original Battlestar Galactica, you may know this reference. I only discovered it while watching a re-run on the Space Channel (a Canadian channel now called Sci-Fi channel) many years (and multiple re-watches) after I first saw Spaceballs. Don't ask me the episode, and I cannot find a video reference to back it up. This was back in 1999, and I haven't seen an episode since, so I can't remember the episode details.

I was watching the episode when one of their ships went into their version of hyper drive. The now-campy special effects was a grid of yellow lines on a black background that immediately made me yell out "They've gone to plaid!" My roommate ran out and looked at the screen and started laughing.