Absolutely not! I use LT exclusively (I go through about 5 gallons per year) to clean wiring harnesses, although some plastic plugs from 70-73 seem to "melt" with LT is applied. In those cases, I use Formula 409 or vinegar. The only wires that LT will remove the color are those wires that are painted at the factory. Typically, they are fuel sensor lines near the trunk area, fusible links, and occasionally lines that go to the coil. All of these wires have very thick rubbery insulation, not the standard PVC insulation. PVC colors and stripes are impregnated into the insulation as they are extruded during manufacture.
Don't believe everything you hear or read on the Internet. Back in 1998, the wifey warned me about going onto forums, as they are frequented by Internet Ax Murderers. Nonsense. They were Chainsaw Murderers.