I'm looking to make some customizations to the desktop modules for the Brisa theme. I would like to:

• Change the bar color of the CPU/Ram meter gauges to a different color
• Add Date and time text to the Analog clock
• Remove certain parameters (e.g. Wind) from the weather module and either reposition the other data or increase text size to compensate for the newly acquired real estate.

Is it possible to do this? If so, how? Alternatively, is there a theming guide that I can read?