Can I change the colors of my QR code?

Yes. In the QR Code Designer, set a foreground colour for the dots and corners and a background colour for the canvas. Both accept any hex value.

Contrast is what makes a QR scan reliably. Keep the foreground noticeably darker than the background — dark dots on a light background is the pairing that scanners are trained on. Inverted palettes (light on dark) often work but are more sensitive to low light, glare, and printing conditions. See Will a colored QR code with a logo still scan? for more on scannability.