Hi Uppu,
Then you are on a different version to me which means you might be able to use Eclipse theme editor. However I would recommend agains it as it is out of support as described in note 1613933.
Instead I developed new theme through SAP Portal using SAP_Streamline as starting point.
There are a few steps for this process and I will try to create a blog this week regarding it so that others can benifit. But so that you can get started I'll just give you the first couple of steps to see if you can get this far.
You need a SAP Portal installation to create the theme there with the theme editor. Do you have that and will you be displaying your WDA applications through the portal or as standalone?
1. Make sure the style sheet version of the portal is the same as or higher than the style sheet
version that the backend uses as described in SAP Note 1446099
2. Develop a new theme in SAP Portal based on standard SAP theme. The theme editor can be located as
explained in SAP Note 1633173.
Please get back to me when you get this far and I will try to guide you further.
Br Jan