syntax: python: color also the special values 'False', 'None', 'True'

And increase the contrast for the reminders, both for PO and Python.

syntax/po.nanorc

@@ -24,6 +24,6 @@ color brightmagenta "%([1-9]\$)?[a-z]*"
 color yellow "\""
 color cyan "\\n"
 # Reminders.
-color ,yellow "(FIXME|TODO|XXX)"
+color brightwhite,yellow "(FIXME|TODO|XXX)"
 # Obsolete strings.
 color red "#~.*$"

syntax/python.nanorc

@@ -23,8 +23,11 @@ color brightred "(^|[[:blank:]])#.*$"
 color brightgreen    start="'''([^'),]|$)" end="(^|[^(\])'''"
 color brightgreen start="\"\"\"([^"),]|$)" end="(^|[^(\])\"\"\""
 
+# Special values.
+color brightmagenta "\<(False|None|True)\>"
+
 # Reminders.
-color ,yellow "(FIXME|TODO|XXX)"
+color brightwhite,yellow "(FIXME|TODO|XXX)"
 
 # Trailing whitespace.
 color ,green "[[:space:]]+$"