The desktop themes define the color and shape of the decorations around the Windows and the color schemes used for the foreground and background of dialog contents. By default Ubuntu uses the Human theme. This is essentially a theme called ''Clearlooks'' with earthy looking colors applied to it. A number of pre-installed themes are also available for selection, and many themes are available for download online.
Exception encountered, of type "Error"
[e8252420] /index.php/Special:MobileDiff/7391 Error from line 434 of /var/www/techotopia/includes/diff/DairikiDiff.php: Call to undefined function each()
Backtrace:
#0 /var/www/techotopia/includes/diff/DairikiDiff.php(544): DiffEngine->diag()
#1 /var/www/techotopia/includes/diff/DairikiDiff.php(344): DiffEngine->compareSeq()
#2 /var/www/techotopia/includes/diff/DairikiDiff.php(227): DiffEngine->diffLocal()
#3 /var/www/techotopia/includes/diff/DairikiDiff.php(721): DiffEngine->diff()
#4 /var/www/techotopia/includes/diff/DairikiDiff.php(859): Diff->__construct()
#5 /var/www/techotopia/includes/diff/DairikiDiff.php(980): MappedDiff->__construct()
#6 /var/www/techotopia/extensions/MobileFrontend/includes/diff/InlineDiffFormatter.php(99): WordLevelDiff->__construct()
#7 /var/www/techotopia/includes/diff/DiffFormatter.php(140): InlineDiffFormatter->changed()
#8 /var/www/techotopia/includes/diff/DiffFormatter.php(82): DiffFormatter->block()
#9 /var/www/techotopia/extensions/MobileFrontend/includes/diff/InlineDifferenceEngine.php(117): DiffFormatter->format()
#10 /var/www/techotopia/includes/diff/DifferenceEngine.php(797): InlineDifferenceEngine->generateTextDiffBody()
#11 /var/www/techotopia/includes/diff/DifferenceEngine.php(728): DifferenceEngine->generateContentDiffBody()
#12 /var/www/techotopia/extensions/MobileFrontend/includes/specials/SpecialMobileDiff.php(241): DifferenceEngine->getDiffBody()
#13 /var/www/techotopia/extensions/MobileFrontend/includes/specials/SpecialMobileDiff.php(135): SpecialMobileDiff->showDiff()
#14 /var/www/techotopia/extensions/MobileFrontend/includes/specials/MobileSpecialPage.php(53): SpecialMobileDiff->executeWhenAvailable()
#15 /var/www/techotopia/includes/specialpage/SpecialPage.php(384): MobileSpecialPage->execute()
#16 /var/www/techotopia/includes/specialpage/SpecialPageFactory.php(553): SpecialPage->run()
#17 /var/www/techotopia/includes/MediaWiki.php(281): SpecialPageFactory::executePath()
#18 /var/www/techotopia/includes/MediaWiki.php(714): MediaWiki->performRequest()
#19 /var/www/techotopia/includes/MediaWiki.php(508): MediaWiki->main()
#20 /var/www/techotopia/index.php(41): MediaWiki->run()
#21 {main}