Why didn't all dependencies get updated?

Question

Composer

Yesterday I discovered a command
$ composer outdate
that allows you to check for updates without updating them (I have dreamed about this possibility all my life)
, in general, I executed the command, I got a list:

well, ok, I'm updating. I launched the update, upon completion, I see that somehow it’s not enough, I check again, and here the list is smaller,

why isn’t everything updated? and what does the yellow and red highlight on the version mean?

Answer 1

probably not compatible.

Answer 2

Ilya Beloborodov , it's time to discover the composer help too: