How to change color and sidebar menu without using themes We have a number of different themes on our website as we have different departments with different color styles. However, the only thing that changes are the colors of the sidebar and which menu is displayed on the sidebar; the layout of these pages remain the same almost exclusively. It seems as though having 16 different themes, which we do, is unnecessary if these are the only things changing (sidebar color and menu). 

Are there any good modules which could achieve this functionality (changing color and menu depending on department) without having all these different themes? Or are themes the only/best way to go to achieve this functionality? Also is having this many themes the average or is that a lot?
There are 16 different departments so 16 different colors are needed. Create one theme for all of them. In your .css file create 16 classes and in each one set a custom background color. Like this

.dp—i{ background-color:#abcdef !important}


Now using preprocess functions, and based on the department add the css class to the page component. If it is a block use preprocess_block, if it is region use preprocess_region. By checking the department and adding approprite css class to the class array it will work