You can create colored QR codes with our API. Just choose a background and / or a foreground color and take care of good contrast between the light and dark modules / pixels. Furthermore, a colorized QR code should be no negative (in terms of color, the actually black pixels / modules have to be darker than the normally white pixels) as the dark modules / pixels contain the data and a negative will confuse many QR code readers:
You can find a detailed function description and examples at our API documentation.