Scan adds a grey background

[paulm5545]

I have a Macbook Pro OS 10.13.6.  I have a document with words highlighted in yellow.  Scanning in color gave me the grayish light tan background.  Unplugging, resetting, etc. did not resolve the issue.   So, after playing with it, I found a solution.  System Preferences - Printers & Scanners - Scan - Open Scanner, I then go to the box directly below Format titled, Image Correction.  Go to Manual, scroll down to Brightness.  I found by moving the Brightness 1 or 2 notches to the right, the background becomes white.   Hope that helps.  Too bad one has to jump through hoops to get. rid of the darkened background using the Color document scan setting.  I hope this helps you and everyone else with the problem of  losing the white background when scanning a document.

[paulm5545]

What I have not been able to figure out, is how to improve the quality of scanning.  Using the steps I mentioned for lightening up the background of my documents has not improved the clarity of the scanned document.  Like everyone else, it prints clear and crisp, but scanning has slightly blurred letters or numbers and slightly lighter colors.  I have not been able to adjust the contrast or sharpness.  BTW, this is a brand new (4/1/2019) HP Envy 7155 printer from Staples.  The suggestion to unplug, wait 30-seconds and try it again is (pardon my choice of words) absolutely ridiculous and useless ~ as evident by the number of people who followed the advice (yes, me too) without any improvement what so ever.  So far, I am really disappointed with HP's "Support."  Seems non-existent and we turn to each other to see if someone has muddled through and figured things out through trial and error.  Anyhow, if anyone has figured out how to improve the quality, or the ability to adjust the contrast or sharpness for scanning, please let me know.  Thank you in advance!