A visible skin-tone difference in that situation is much more likely caused by the camera body/settings and the lighting than by the lenses themselves.

Two big factors:

1. White balance/exposure processing: If the cameras were on auto settings, each body may have chosen different white balance, metering, or exposure compensation. Under warm indoor light, that can strongly affect skin tones.
2. Fluorescent light flicker: Fluorescent lighting changes brightness and color rapidly with the AC cycle. Two shots taken moments apart can look different even with the same camera, lens, and settings—especially at faster shutter speeds.

So the difference you saw is not good evidence that one lens has better low-light color than the other. To compare fairly, use the same camera body, manual exposure, fixed white balance, and ideally constant non-flickering light. Shoot RAW if possible.

In short: the lenses are unlikely to be the reason for the brown/fair skin tone shift you observed.