Update doxygen colorsand style

Signed-off-by: Tobias Frisch <tfrisch@uni-koblenz.de>

Doxyfile

-# Doxyfile 1.9.5
+# Doxyfile 1.9.6
 
 # This file describes the settings to be used by the documentation system
 # doxygen (www.doxygen.org) for a project.
@@ -86,7 +86,7 @@ CREATE_SUBDIRS         = NO
 # level increment doubles the number of directories, resulting in 4096
 # directories at level 8 which is the default and also the maximum value. The
 # sub-directories are organized in 2 levels, the first level always has a fixed
-# numer of 16 directories.
+# number of 16 directories.
 # Minimum value: 0, maximum value: 8, default value: 8.
 # This tag requires that the tag CREATE_SUBDIRS is set to YES.
 
@@ -568,7 +568,8 @@ HIDE_UNDOC_MEMBERS     = NO
 # If the HIDE_UNDOC_CLASSES tag is set to YES, doxygen will hide all
 # undocumented classes that are normally visible in the class hierarchy. If set
 # to NO, these classes will be included in the various overviews. This option
-# has no effect if EXTRACT_ALL is enabled.
+# will also hide undocumented C++ concepts if enabled. This option has no effect
+# if EXTRACT_ALL is enabled.
 # The default value is: NO.
 
 HIDE_UNDOC_CLASSES     = NO
@@ -859,6 +860,14 @@ WARN_IF_INCOMPLETE_DOC = YES
 
 WARN_NO_PARAMDOC       = YES
 
+# If WARN_IF_UNDOC_ENUM_VAL option is set to YES, doxygen will warn about
+# undocumented enumeration values. If set to NO, doxygen will accept
+# undocumented enumeration values. If EXTRACT_ALL is set to YES then this flag
+# will automatically be disabled.
+# The default value is: NO.
+
+WARN_IF_UNDOC_ENUM_VAL = NO
+
 # If the WARN_AS_ERROR tag is set to YES then doxygen will immediately stop when
 # a warning is encountered. If the WARN_AS_ERROR tag is set to FAIL_ON_WARNINGS
 # then doxygen will continue running as if WARN_AS_ERROR tag is set to NO, but
@@ -1230,10 +1239,11 @@ VERBATIM_HEADERS       = YES
 
 ALPHABETICAL_INDEX     = YES
 
-# In case all classes in a project start with a common prefix, all classes will
-# be put under the same header in the alphabetical index. The IGNORE_PREFIX tag
-# can be used to specify a prefix (or a list of prefixes) that should be ignored
-# while generating the index headers.
+# The IGNORE_PREFIX tag can be used to specify a prefix (or a list of prefixes)
+# that should be ignored while generating the index headers. The IGNORE_PREFIX
+# tag works for classes, function and member names. The entity will be placed in
+# the alphabetical list under the first letter of the entity name that remains
+# after removing the prefix.
 # This tag requires that the tag ALPHABETICAL_INDEX is set to YES.
 
 IGNORE_PREFIX          =
@@ -1312,7 +1322,12 @@ HTML_STYLESHEET        =
 # Doxygen will copy the style sheet files to the output directory.
 # Note: The order of the extra style sheet files is of importance (e.g. the last
 # style sheet in the list overrules the setting of the previous ones in the
-# list). For an example see the documentation.
+# list).
+# Note: Since the styling of scrollbars can currently not be overruled in
+# Webkit/Chromium, the styling will be left out of the default doxygen.css if
+# one or more extra stylesheets have been specified. So if scrollbar
+# customization is desired it has to be added explicitly. For an example see the
+# documentation.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
 HTML_EXTRA_STYLESHEET  =
@@ -1328,21 +1343,17 @@ HTML_EXTRA_STYLESHEET  =
 HTML_EXTRA_FILES       =
 
 # The HTML_COLORSTYLE tag can be used to specify if the generated HTML output
-# should be rendered with a dark or light theme. Default setting AUTO_LIGHT
-# enables light output unless the user preference is dark output. Other options
-# are DARK to always use dark mode, LIGHT to always use light mode, AUTO_DARK to
-# default to dark mode unless the user prefers light mode, and TOGGLE to let the
-# user toggle between dark and light mode via a button.
-# Possible values are: LIGHT Always generate light output., DARK Always generate
-# dark output., AUTO_LIGHT Automatically set the mode according to the user
-# preference, use light mode if no preference is set (the default)., AUTO_DARK
-# Automatically set the mode according to the user preference, use dark mode if
-# no preference is set. and TOGGLE Allow to user to switch between light and
-# dark mode via a button..
+# should be rendered with a dark or light theme.
+# Possible values are: LIGHT always generate light mode output, DARK always
+# generate dark mode output, AUTO_LIGHT automatically set the mode according to
+# the user preference, use light mode if no preference is set (the default),
+# AUTO_DARK automatically set the mode according to the user preference, use
+# dark mode if no preference is set and TOGGLE allow to user to switch between
+# light and dark mode via a button.
 # The default value is: AUTO_LIGHT.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_COLORSTYLE        = AUTO_LIGHT
+HTML_COLORSTYLE        = TOGGLE
 
 # The HTML_COLORSTYLE_HUE tag controls the color of the HTML output. Doxygen
 # will adjust the colors in the style sheet and background images according to
@@ -1372,7 +1383,7 @@ HTML_COLORSTYLE_SAT    = 100
 # Minimum value: 40, maximum value: 240, default value: 80.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_COLORSTYLE_GAMMA  = 220
+HTML_COLORSTYLE_GAMMA  = 100
 
 # If the HTML_TIMESTAMP tag is set to YES then the footer of each generated HTML
 # page will contain the date and time when the page was generated. Setting this
@@ -1381,7 +1392,7 @@ HTML_COLORSTYLE_GAMMA  = 220
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_TIMESTAMP         = NO
+HTML_TIMESTAMP         = YES
 
 # If the HTML_DYNAMIC_MENUS tag is set to YES then the generated HTML
 # documentation will contain a main index with vertical navigation menus that