Convert xc to rgbo

What is the difference between .xc and .rgbo?

Name: X Server Constant Screen Image Bitmap; Raw red, green, blue, and opacity samples

Description: This file format is used as a canvas (background) in a variety of image editing software in order to set the main color of the image. It is used to fill the canvas with one solid color. It belongs to the group of 'pseudo-image' file formats. It can be used for the fill color, which is chosen from the selected area in a particular image.; Format for representing colors in the three primary colors (red, green and blue), each of which has 255 gradations. In contrast to the standard RGB, it allows you to change the transparency of the entire image using the opacity parameter.