Your scanner software settings are the most likely culprit. You are right to expect that a reasonably good consumer-grade scanner scanning software monitor viewing software and cloud business card service should all be reasonably consistent. Scanners can color profiles in the images they make that tell your viewer and your cloud service what the colors should look like but most consumer grade scanners don do this. They rely instead on having spectral response after processing that is reasonably close to a widely used standard color profile called sRGB. A decent scanner should either have near-sRGB response or it should color profiles that tell your viewer and your cloud service what the response is. Decent consumer grade monitors are calibrated right out of the box even if not to high precision and in effect so are decent scanners. However a lot of scanners are set up to make JPEGs by default whereas Jpeg is the very worst format for line art like business cards so take the time set your scanner to make either Tiff or PDF. If your scanner won do that get another one. This will improve the quality of the line art. Your scanner software could even add a color profile to either the PDF or the Tiff which should improve the consistency of your view and the cloud based view if both your viewer and your cloud service support this. However the proper use of ICC color profiles is little-understood even by professionals and so they are not as often used as they should be.