Lubuntu allows you to configure the appearance of each LXDE component separately. Most of the configurations relating to appearance are found by clicking on Menu, Preferences, Customize Look and Feel.
Default Font Size
To change the default font size, see Lubuntu/Setup#Fonts
Openbox Window Titles
Openbox themes can be found at box-look.org or see the list of websites here: https://wiki.archlinux.org/index.php/Openbox_Themes_and_Apps#Openbox_themes.
Openbox themes can be installed automatically by double-clicking the ".obt" file (or by using "Openbox Configuration Manager" or the window border tab on "Customize Look and Feel") , unless you get a themerc file, which needs to be installed manually.
If you get a zip with a themerc file, you'll have to do something like this to move the uncompressed theme (a directory containing a themerc) into the /usr/share/themes directory:
unzip theme_by_dude.zip ls sudo cp -r SomeTheme_Openbox /usr/share/themes
(the same can be done with PCManFM if you open the /usr/share/themes folder as root)
More info at the Openbox Wiki
- After the theme is installed. Select it with "Openbox Configuration Manager" or "Customize Look and Feel"
LXPanel (the bottom taskbar) uses bitmaps to theme itself. You will need to pick out a bitmap for the button, and second bitmap for the bar.
First, download an image you'd like to use as a "start" button. Right click directly on the Lubuntu start button, and select "Menu" Settings.
Click browse to select the image file. The image will be shrunk in proportion to fit the panel. You're done.
http://tools.dynamicdrive.com/gradient/ and http://www.generateit.net/gradient provide tools to generate gradients on the web. The bar bitmap needs only to be 1 pixel wide.
Right-click on the bottom panel left of the window list. Select "Panel Settings" from the pop-up menu. On the "Panel Preferences" dialog, switch to the "Appearance" tab, and you will see an button to select an image background. Select the file and you're done.
PCManFM draws the desktop in Lubuntu. If you don't see "Desktop Preferences" context menu when you right-click the PCManFM desktop, you will have to run this command: pcmanfm --desktop-pref
On the "Desktop Preferences" dialog, there is an option to select your desktop background or wallpaper. There also is a desktop icons tab in version 14.04 or later that lets you toggle a trash can, Documents folder, and removable media having icons on your desktop.
You can select the look and feel of buttons and widgets in Lubuntu by installing a GTK+ widget pack.
If you aren't satisfied with the default theme, you could look in the software center for additional themes. light-themes will provide you with Ambiance and Radiance. shimmer-themes will get you Greybird, Bluebird, and Blackbird. By default, these themes will be installed in /usr/share/themes. If you prefer, you can copy them over to ~/.themes for a single user and rename the copied theme folder to be distinctive. So, if you have Ambiance in /usr/share/themes, you could rename the copy in ~/.themes to MyAmbiance.
Note: ~/.themes is a hidden folder and normally not visible in a file manager. Control+H toggles its visibility. It's also possible that it may not exist by default. You can create it by using PCManFM or by running mkdir .themes from a terminal opened to your home folder.
If you want to look further afield, try gnome-look.org or search DevianART. Note that the themes found at these two sites won't install automatically. You'll need to download compressed files, and extract them to the required destination. It is advisable to look for a theme that covers both GTK2 and GTK3 because it's probable that you will encounter both types of apps. Also, try to avoid old themes. A further caveat when installing themes not from the Software Center is that you may need to have the appropriate "engine" which should be available from the standard repository. So do check the READMe files that come with themes installed from elsewhere.
Again, first look in the Software Center. Other icon themes are available as compressed files from gnome-look.org or DevianART or from the designer's own site. As for the GTK2 and GTK3 themes, you will need to uncompress the downloads and move the relevant folders to ~/.icons or /usr/share/icons.
To install the icon theme, open "Customize Look and Feel" and select the "Icon Theme" tab. You will see an "Install" button on the left. Select the icon theme you wish and click Apply.
http://maketecheasier.com/theme-up-lubuntu/2011/02/11 has an old but useful description of the Customize Look and Feel interface.
http://pclosmag.com/html/Issues/201010/page07.html describes how to tweak the appearance of lxpanel.