PressRun supports an RGB color space - when you click the 'validate' button in the PressRun Exporter, are there any 'non-RGB color swatch' errors? If so, in your 'Swatches' palette, try double-clicking your CMYK swatches, and in the 'Color Mode' dropdown, change to 'RGB' and hit 'OK'. Your colors are now RGB and should display correctly after re-exporting your file.