In Mathematica, specializing Sections, Subsections, Titles and so on, will be done with Format > Style > ....., which everyone can do it. Also, one can change the background color of that. I bring an example of this purpose and I colored it orange:

But I want to change its color with the gradient format. I mean, instead of having smooth orange in all of the background, we have a gradient colored background. The gradient style will be found in Palettes > Color Schemes. But for changing the color of the background, it doesn't work.

In Mathematica, customizing Sections, Subsections, Titles and so on, can be done with Format > Style > .... Changing the background color of a style is one of the things you can do. Here is an example where I have colored the background orange:

But I want to change the background to show a color gradient. I mean, instead of having the same orange in all of the background, there should be a gradient so the orange fades from top to bottom. Gradient styles will be found in Palettes > Color Schemes. But I can't get it to work for changing the color of a cell background.