What do these file colors mean?

[dandv]

I've just copied a bunch of pictures from my Android to a hard disk and noticed their colors are apparently randomly both purple and blue (i.e. pictures, and "Today").

However, the creation, write and access times for the files are the same - 2015-02-22.

After restarting MC, all files look correctly purple ("images").

[Mathias (Author)]

MC copies all files in the background and will update/refresh if it detected new files.
And since the copy from portable devices are slow it might refresh before the files are completely written. And before it is written completely file date/time is the time it started to write it. Old time is not set until after file is done.
But since view is refresh file coloring will give it "Today" color.
It will fix it self after a while...(timed colors are revalidated every couple of minutes)  Or you can press the colorwheel on toolbar and select refresh file coloring.