Nice idea.  Some of the colours look very similar though.  Add different lighting conditions and you probably couldn't tell the greens or pinks apart.  Probably better to forget the HTML colours and define your own colours with their set % of red green and blue.  Then work out some way of showing where the colour QR code starts and stops.

QR codes still win

many people have their computer screens at different brightnesses.

people watching movies prefer a different contrast ratio than others.. otherwise movies like batman cant tell the difference between his black costume and the nights sky.

people doing office work dont want bright white screen blazing into their eyes so they tone it down to a grey scale of brightness

this causes someone if they are then to scan using a camera phone a colour code from another screen the colour seen isnt accurate.
even when scanning from one phone to another is not accurate due to battery saving brightness levels
for instance just screen brightness can confuse colour scanners as these (above and below) can become interchangeable

a #00fdff █ | e #818181 █ |
q #80ffd4 █ | f #1d8c1d █ |

yet at most different brightness levels QR codes still scan correctly or show an error
colour scanning wont show 'error' but just show a result with characters in the wrong places which then makes people have to double check the character ordering anyway,

if you are in any concern you might aswell just use some OCR software as oppose to this colouring idea. as OCR has less fault issues/concerns.. but preferably QR codes are best