I calibrated mine -- there&#x27;s a little calibration screw on the back labeled with &quot;Gamma, X-ray, UV, Visible, IR, Microwave, UHF, VHF, HF, ELF&quot;<p>It&#x27;s only got about 120 degrees of rotation, so it&#x27;s tricky trying to tune it to emit a particular color.<p>I had it turned to ELF for a while, but then the Navy called and said my flashlight was disrupting their submarine communications.