Custom Fiori App not loading with custom theme

Hi Experts,

We have developed an extended PR Approval app which works fine.I created a custom theme based on sap_bluecrystal.

The theme changes load fine for the standard PR approval app but the custom app does not pick up the theme changes,custom Fiori app still loads with sap_bluecrystal even though the launchpad and the standard app loads fine with the new css.

Our server is on  NW 7.4  SP11 for SAP_UI and the SAPUI5 library has been updated to 1.26.8 .

Please provide your expert advice as how i can make the custom fiori app to pick up the custom theme.

Regards

Radhika