Find out what is setting color in minibufer

[Fernando Basso]

I have been using Emacs from the terminal recently. It works fine and it
helps me with my tmux workflow. However, when I am using Geiser mode the
minibuffer shows documentation hints in a shade of blue that makes it hard
to read. I don't know if it is Geiser or something else that is setting
that color. It seems the color remains even if I load a different theme.
Also, that color is not set in my Xresources file.

How should I proceed to find out what is setting that color? Emacs 25 on
arch linux.

I am attaching a screenshot in the hope that it will help.

Thanks in advance.

geiser-docs-color.png
Description: PNG image