The old Starlight / Silver Starlight are built with exactly the same design as the current Ultraviolet cable. The Ultraviolet is 4K certified by DPL Labs. Several of these cables should be fine at 4K.
The reason these cables are so good is that they are heavy silver clad and use large 24awg conductors. The Heimdall uses 25awg and the Neotech uses 26 awg, but they are still excellent.
Many cables use smaller conductors (such as 30awg in the Audioquest vodka). The sound just doesn't have as much oomph and the video is not as good.