Hall Research UVA-WP - Manual (Page 13)

Wallplate VGA and Audio on UTP Transmitter
11
3. Operation
3.1 UTP Cable Recommendations
UTP cables have 4 twisted pairs inside. The UVA/URA video
transmission on UTP uses 3 individual pairs for each color (Red,
Green, & Blue). As shown above, a characteristic of Category-5/5e/6
cable is that the pairs of wires are twisted at different rates. Therefore,
for a given length of Cat-5 cable the total length of a particular pair
could be longer than others. Since the signals travel in the cable at a
fixed speed, the arrival times of signals can be skewed in a long cable
(those that have to travel farther arrive later and the corresponding
color shifts to the right).
This is seen on the monitor as separation, or lack of convergence in
colors. For example a vertical white line on the screen may look to
have a red tinge on the left edge and blue tinge on the right edge.