ONEWEB mainly controls the look and feel of the forms through CSS. Cascading Style Sheets (CSS) is a language for describing how content is presented. It's purpose is to help separate content (HTML) from presentation.

ONEWEB provides a default custom CSS which the users can edit to create their individual styles. The name of the file is <CurrentTheme>_Custom_Style.css. To find the file, open Eclipse IDE, on the Project Explorer Pane, go to on /MasterWeb/WebContent/theme/<CurrentTheme> folder, and open <CurrentTheme>_Custom_Style.css. For the example below CurrentTheme is Responsive2016.

This file is blank when you start with ONEWEB. You can add any custom css that you want to apply to your project here. The styles that you define here are applicable across all Smart Forms. For e.g. to change the header colour please add the below snippet to the custom css file.

Or to add default background to all textfields add the following snippet.

Once the changes are saved, right-click the server and select Publish from the menu. The state changes to Synchronized once the project has been deployed to the server. Note: Don't forget to clear the browser cache for the new CSS style to come into effect.