With the introduction of the MapInfo Pro Viewer (see 17.03 release notes), we needed to visually distinguish between the two ways of running Pro. As such we have introduced new styling to MapInfo Pro and the MapInfo Pro Viewer.
The Viewer uses a subdued gray theme, while Pro has been updated to use a little more colorful blue theme.
If for any reason the old styling for Pro is desired you can change the "OverrideDefaultStyle" key to "true" in the styles\MapInfoProStyle.xml file under the Pro installation folder. (Same for runtime)
Inside this file is also a detailed description of the style changes we have made for Pro and the Viewer.If you are creating an app/addin with Pro or Runtime and you are rebranding it so end users see it as a separate product, you can take advantage of the same MapInfoProStyle.xml file to adjust the colors of the UI.We also have a sample with mapbasic under Samples\RIBBONINTERFACE\DotNet\RuntimeRebranding that shows how to do this.