I dont think so, as IMHO appearing white and accelerated time dilation from an event horizon like this are mutually exclusive.
I'm not 100% certain of the physics behind this (I only have half a physics degree), so this may be wrong. But I think this is logically inconsistent.
If time dilation was occurring in this manner, the photons would be transformed by the time dilation, similar to a gravitational redshift.
If the time dilation is tending to infinite at the event horizon, and its seen to observers as white (so an approx even mix of all visible light), what frequency were those photons initially emitted at, such that when slowed down to "normal" speeds, they appear an even mix of pure white?
In other words, how can I multiply any set of numbers by infinity and get all real numbers?
If anything, perhaps some quantum tunneling is at play allowing the photons to go skipping the "divide by infinity" issue at the event horizon, your going to run into banding issues from planc wavelengths, which make it unlikely to form uniform white to the human eye.
This absurdity leads me to believe that this is impossible, so if white holes do exist, it wouldnt be possible for their time dilation to behave as suggested.