Have I used it? No, since my Ender has white accents. But here is a nice looking dual-gear extruder in blue for $16 on Amazon - https://www.amazon.com/dp/B0B6PBKJYG

Also spotted some blue leveling knobs (https://www.amazon.com/dp/B0967TJS37), socks (https://www.amazon.com/dp/B09B3H6VBP), and a hotend (https://www.amazon.com/dp/B0B2S5M5LQ).

Even spotted what is a Dual Z w/linar rails kit (no rails included) that has all the aluminum plates done in blue - https://www.amazon.com/dp/B08LPGHGY1/