X/Z color demodulation.

[old_tv_nut]

The offset does nothing to reduce noise or crosstalk, but it does affect color reproduction.

Because the nominal X and Z axes are less than 90 degrees apart, the phase shift can be obtained with a simple RC circuit. In chassis that use an RC instead of a coil quadrature adjustment, no adjustment is needed, and you can actually calculate the phase offset from the schematic values. With no adjustment, there is some variation with parts tolerances, but such an untuned two-passive-component circuit has the least sensitivity to component values of any possible arrangement.

Regarding the effect on color reproduction: spreading the angles to greater than 90 degrees and shifting the over-all phase properly results in a suppression of green and magenta, and is the simplest form of automatic tint control, which was used much later when "one-button color adjustment" was all the rage. It reduced variation in skin-tone tint, but tended to result in the "tan cowboy on a brown horse on the beige range riding into the orange sunset" kind of color reproduction. It is mathematically equivalent to reducing the Q channel gain in an I/Q demodulator.