I recently received a vector logo from a client where the main object was broken into many pieces with each piece having a separate color. To simplify the logo, I wanted to Weld all of the objects together in CorelDRAW so they were a single object. But if they are welded, the numerous colors would be lost.
The solution was to create a series of rectangles. Using Eyedropper, I captured colors from the original logo and filled each of the rectangles. Then I used those rectangle to build a multi-step fountain fill in the version of the logo that was a single shape. The graphic below shows the original on top and the single object version on the bottom with the series of rectangles in the middle.