Multiple builds from one branch but different CSS values
If I correct understand Your problem, You want to build app with diffrent ccs and images.

Jenkins suports maven and simplest way is to use maven profiles plus maven-war-plugin 
eg.:

&lt;build&gt;
&lt;plugins&gt;
    &lt;plugin&gt;
        &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
        &lt;artifactId&gt;maven-war-plugin&lt;/artifactId&gt;
        &lt;configuration&gt;
            &lt;webResources&gt;
                &lt;webResource&gt;
                    &lt;directory&gt;src/main/profile/webapp/${images.folder}&lt;/directory&gt;
                    &lt;targetPath&gt;images&lt;/targetPath&gt;
                &lt;/webResource&gt;
            &lt;/webResources&gt;
        &lt;/configuration&gt;
    &lt;/plugin&gt;
&lt;/plugins&gt;




&lt;profiles&gt;
&lt;profile&gt;
    &lt;id&gt;prod_client_1&lt;/id&gt;
    &lt;properties&gt;
        &lt;images.folder&gt;prod_client_1&lt;/images.folder&gt;
    &lt;/properties&gt;
&lt;/profile&gt;
&lt;profile&gt;
    &lt;id&gt;prod_client_2&lt;/id&gt;
    &lt;properties&gt;
        &lt;images.folder&gt;prod_client_2&lt;/images.folder&gt;
    &lt;/properties&gt;
&lt;/profile&gt;




For other resources filtering maven-resources-plugin

At least should be helpful this approach sharing resources across projects