The colors selected by the artists had a direct bearing on the characters portrayed. According to ancient texts there are three broad qualities assigned to superhuman, human and sub human beings, viz Satwa (the noblest), Rajas (the active and middle principle) and Tamas (the dark and destructive principle) respectively.
To represent Satwik quality green and shades of green were used. Characters of a Rajasik quality were portrayed in red or golden and the Tamasik nature of the gods were represented not by black but in white, white demons and demonesses were represented by black.
Among the subjects, Vishnu and his Satwik incarnations, Parvati, Sridevi, Arjuna, pious beings like Prahlada and Markandeya were always painted in green. Bhoodevi (goddess earth) Ganga, Ganesa and the four-headed Brahma were also painted in red. Vishnu was painted in different colors according to his attributes.
It is true that the figures of the murals have the external like-ness of men and women, the divine or rather the supra-human aspect is also obvious in every detail. The creators of these pictures no doubt had undergone rigorous mental disciplines or sadhana.
They had the creative skill to fill every available space with as many details as possible and also the skill to pinpoint on one or two essential details and leave the rest to our imagination. The painting in the Mattancheri palace of Krishna holding aloft Govardhan for example is a typical example in which minute details of wooded mountain are elaborately depicted. This tendency for detailed elaboration is also a characteristic feature of Koodiyattom, the ancient temple theatre of Kerala. Another later but frequent characteristic of the murals of Kerala are the beaded of decorative outlines not only around each panel but also around individual figures.
During the 15 th and 16 th centuries when the second Bhakti movement swept through Kerala, many were the excellent murals that were painted then. It is also highly probable that the leading names of the movement like the eighteen and half poets of the Zamorin’s court, Ezhuthachan, Melpathoor, Poonthanam and the venerable sage Vilwamangalam must have ben instrumental in reviving this popular tradition of religious arts.
The decadence of this tradition that started on the late 18th century gained momentum with the Mysore invasion (1766-1782) of Malabar and the take over of the Travancore temple trusts by the then British Resident (1811). A final blow was inflicted when Raja Ravi Varma’s (1848-1906) portrait style of painting gained fame and popularity.