By default, outlines are filled with solid colors, however if you need to apply a gradient fill to them, follow these steps:
1. Select object and go to: Object > Convert outline to object – or use the shortcut: [Ctrl + Shift + Q] This action transforms the outline to a new object (*) 2. Select the new object and press [F11] to perform a gradient fill and edit colors as you wish. (*) This is also useful if you need to resize object and keep “outline” with proportional thickness.
Tip provided by Silvio Gomes, CorelDRAW Master, Artist and Graphic Designer.
I have seen this instruction ask for many times, well done.