If you want to change the page colour, click Page Colour and select the required background colour.
If you want to add a watermark (transparent image or text), click Watermark and choose one of the predefined watermarks, or select Custom Watermark.
If you're adding a custom watermark, choose a picture or enter the watermark text and select the required formatting options.
Watermark image too big?
Images used as watermarks will be resized to A4 size. If the image on your form is too big, adjust the image size before adding it to the form. There are free picture tools which can do this, like Microsoft Paint.