[gtksourceview] cobalt.xml: modernize error/warning/note

[Christian Hergert <chergert src gnome org>]

commit 9f3e602d8ca8de7fec82dea34096cd470a094a47
Author: Christian Hergert <chergert redhat com>
Date:   Tue Sep 13 23:43:50 2022 -0700

    cobalt.xml: modernize error/warning/note
    
    These can use error underlines instead of the blocky forms that are there
    already as we've done in other schemes.

 data/styles/cobalt.xml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/data/styles/cobalt.xml b/data/styles/cobalt.xml
index cfce17de..55fd4623 100644
--- a/data/styles/cobalt.xml
+++ b/data/styles/cobalt.xml
@@ -118,9 +118,9 @@
   <style name="def:list-marker"             foreground="bright_orange"/>
 
   <!-- Others -->
-  <style name="def:error"                   foreground="white" background="dark_red" bold="true"/>
-  <style name="def:warning"                 foreground="white" background="nail_polish_pink"/>
-  <style name="def:note"                    foreground="neon_yellow" bold="true"/>
+  <style name="def:error"                   underline="error" underline-color="dark_red"/>
+  <style name="def:warning"                 underline="error" underline-color="neon_yellow"/>
+  <style name="def:note"                    underline="error" underline-color="steel_grey"/>
   <style name="def:net-address"             foreground="teal_blue" italic="false" underline="single"/>
   <style name="def:preprocessor"            foreground="light_grey"/>
   <style name="def:underlined"              underline="single"/>