'No,' she said, as we waited, 'that’s not right.'
Not fading, but returning, rising through
full spectrums of radiant light until,
to the human eye it appears to fade
       (pale white to a silver grey)
but it simply steps into a vision
that is reserved for keener eyes than ours.
       (like ultraviolet)

Not fading, but transforming, travelling
at a speed forever known as its own.
Always keen to get home in a fit state
to enjoy a few hours with its feet up
by the ebb and glow of its evening fire
       (red with blues and greens)
before rising, rested, to greet the dawn
recharged with the full force of the sunrise.
       (bold yellow and blood orange)

No, not fading.  That fails to see the truth
that it’s taking paths through deeper shadows
       (purples and blues mostly)
which our deceptive eyes struggle to grasp
and in our weakness, it is lost to us.

Then she gasped, and I saw that she was right,
the light didn't fade, but it stepped ahead
waiting at the next bend of hope’s rainbow.
       (a glow of pure gold)