In partial discharge (PD) phenomenon energy is emitted as electromagnetic emission, acoustic emission and chemical reactions as ozone formation and nitrous oxide gases. One of the continuous conditions monitoring process is done in high voltage equipments such as power transformer. This paper deals with a short review on PD detection methods regarding high-voltage equipments such as electrical detection, chemical detection, acoustic detection and optical detection. Also, new technique for PD signal monitoring in power transformer call as chromatic in the present. The chromatic approach shows the ability to quantifying information content of PD signal by chromatic parameters hue (H), saturation (S) and lightness (L), which can be related to characteristics of PD signal. The chromatic approach shows the ability to yielding new patterns, which monitoring indications of the discharges signals with high accurac and without noise.