jQuery Mobile framework takes the "write less, do more" mantra to the next level: Instead of writing unique applications for each mobile device or OS, the jQuery mobile framework allows you to design a single highly-branded responsive web site or application that will work on all popular smartphone, tablet, and desktop platforms.
Themes & swatches
The theme system separates color and texture from structural styles that define things like padding and dimensions. This allows theme colors and textures to be defined once in the stylesheet and to be mixed, matched, and combined to achieve a wide range of visual effects.
Each theme includes several global settings, including font family, drop shadows for overlays, and corner radius values for buttons and boxes. In addition, the theme can include multiple color swatches, each with color values for bars, content blocks, buttons and list items, and font text-shadow.
The default theme includes 5 swatches that are given letters (a, b, c, d, e) for quick reference. To make mapping of color swatches consistent across our widgets, we have followed the convention that swatch "a" is the highest level of visual priority (black in our default theme), "b" is secondary level (blue) and "c" is the baseline level (gray) that we use by default in many situations, "d" for an alternate secondary level and "e" as an accent swatch. Themes may have additional swatches for accent colors or specific situations. For example, you could add a new theme swatch "f" that has a red bar and button for use in error situations.
Most theme changes can be done using ThemeRoller, but it's also simple to manually edit the base swatches in the default theme and/or add additional swatches by editing the theme CSS file. Just copy a block of swatch styles, rename the classes with the new swatch letter name, and tweak colors as you see fit.
Assigning color swatches through the data-theme attribute is one way to leverage the theme system, but it's also possible to apply any of the theme swatches directly to your markup through classes to apply the colors, textures and font formatting of your theme to any markup. This is especially useful when creating your own custom layout elements or UI widgets.