I took some times for making a status of the surface discoloration disk
observed recently.
The comparative sketches are colored in order to show the color evolution
on the period from 28th April to 10th May.
Maria are not brownish or greenish as the exit pupill of the scope is
turning on the range 0.5-0.8mm sothat features was appearing with grey
tones. Their contrast levels are amplified to see the decrease amount, on
the period 3rd-8th May they were fainter than normal.
On 10th I saw that the surface disk was on turning back to more pink-orange
color as usual.
The color of Mars seen with naked eyes followed this evolution.
Sketches are more clearer than long explanations.
For your perusal.

[Stanislas Maksymowicz  Ecquevilly,France]