In Applications Manager v8.0 SP7 and above and in all v9 releases the AM client can be updated to display a different color to allow different clients from different environments (Production, Development, Testing) to use a unique color. In order to do that, follow the steps outlined below in Option 1 for each environment you want to change and set the theme color option in the Options.property file to a unique color for each unique environment. This will support Aqua, Ruby and Emerald color themes.
In addition, you can use Option 2, to use the 'steel' theme in the client.jnlp file instead of java and the client will display a purple color scheme. Using this option, you do not need to make any changes to the Options.property.