[old_tv_nut]

Color film inherently has color resolution equal to luminance resolution since the three dye layers (CMY) all have the same resolution. Conversion to digital typically uses full resolution luma and half-by-half resolution chroma (called 4:2:0), which is hardly ever noticeable as degraded.

As DVtyro stated, analog color systems reduce the horizontal chroma resolution drastically. And VHS looks much worse than full bandwidth analog, in both luminance and chrominance resolution.

I would note that early digital satellite transmission (especially the early "MPEG 1.5" of General Instrument) often looked worse than full bandwidth analog transimission. This was due to highly visible artifact levels, mainly due to the unrefined encoding algorithms, not the ultimate capability of the digital coding. Early coders were prone to things like I frame pulsing, "mosquito noise," and noticeable sudden decrease in quality immediately after scene changes. These were all alleviated by better codec algorithms that had better buffer management to allocate data among frames and better allocation of data between pixel data and auxiliary data such as motion vectors.