Objective-c - How to uniformly configure xcode xib colors using files

Question

Since I have always been accustomed to using xib layout, the colors are naturally set in xib, so once the app style is modified, the overall color also needs to be modified. As a result, it is cumbersome to uniformly modify the colors in xib. It needs to be modified individually. I am thinking Is it possible to map the color settings in xib to a file? If I need to uniformly set or modify the colors in xib, I can just modify that file directly,