Hmm, the colors on the Axure RP widgets do look different from the colors in your Sketch file. Just to confirm, are you experiencing this issue with individual widgets, rather than with the Axure RP 9 beta interface? Can you please confirm that the opacity for these widgets and their text is at 100%? If the widgets or text colors are at an opacity less than 100%, the colors could appear as faded or pale.
If that doesn’t resolve the issue, could you please let me know if these widgets are originally Axure RP 9, or if these widgets were added into your Axure file using the Sketch plugin? If the Sketch plugin was used, could you please send your Axure RP file and Sketch file over to email@example.com so that we can take a closer look?
Similarly, if the widgets are originally from Axure RP 9, could you please send your RP file to firstname.lastname@example.org for review? In this case, any additional insight into how these colors were added to these widgets would be useful. If the color picker’s eyedropper tool was used, for example, please let us know what image or file was used for the eyedropper selection.