Here's a tool you might find helpful ... the easy-to-use Wix QR Code Generator.
Generate a QR code for ANY website page including an event or blog post page. Just enter the exact URL into the window.
You can change the color to match any design including a specific Hex code, here's how:
Go to the generator site and click "CREATE A QR CODE"
Under COLORS - click on either "dots" or "background"
Click twice on the tiny arrow to the right of "R G B" until you see the word HEX.
Type in your HEX code - push enter.