Woods Lamp Tinea Versicolor. Look at the skin with a special device called a wood's lamp. If the patient has tinea versicolor, the affected skin appears yellowish green in color when looked at with this lamp.

Scrape off a bit of the skin. If the patient has tinea versicolor, the affected skin appears yellowish green in color when looked at with this lamp. Look at the skin with a special device called a wood's lamp.