Changing syntax hi-lite of shell-mode

[reader]

I've forgotten how to go at this... or may never knew. I want to
change the syntax hi-lite I see in shell-mode.

The directories are displayed in a bold blue that is really bad in a
dark background. (I use darkslategrey)

C-u C-x =
Tells me about the text properties including the color:

 There is an overlay here:
  From 2653 to 2659
   face                 ((foreground-color . "blue") bold)
   modification-hooks   (ansi-color-freeze-overlay)

but not the name of the field being colored (so far as syntax term)
I thought there was something useful at the `C-<mouse1>' menu but
apparently not in shell-mode

M-x describe-face
The first line says:
  Face: bold (sample) (customize this face)

The sample is grey and when I use the `customize this face' link I see
it is set to grey60.  But what I see is bold dark blue.  So setting
that customization has no effect on what I see.

Can someone coach me as to how to set the colors seen in shell-mode?