a) Aerial mass colour:
For the grouping and identification of actinomycetes the Chromogenicity of the aerial mycelium is considered to be an important character. The colours of the mature sporulating aerial mycelium are white, gray, red, green, blue and violet following Prauser (1964). When the aerial mass colour falls between two colours series, both the colors are recorded. In the cases where aerial mass colour of a strain showed intermediate tints, then in that place both the colour series should be noted. (Shirling and Gottileb, 1966).