I want to create gradient with multiple colors. How can I make it with inkscape? One obvious solution is to add more stop points.
Apply a gradient with the Gradient Tool to a shape/closed path. Then with the Gradient Tool still selected, double click on on the gradient line to add a stop, and choose a fill colour from the colour palette along the bottom of the screen.
After you have added stops, you can also select individual stops in the dropdown in the Tool Controls Bar along the top, and edit the fill of the stop more accurately in the Fill and Stroke dialog.