It is often suggested that artists use a limited palette (just a few colours) to create harmony in a work of art. I discovered the need to have colours in all parts of the painting either mixed with a colour or in small patches to create harmony by my own experimentation! But I decided to do a few limited palette paintings to see what would happen and to get to know the limits of the colours I used. I don't like it! Looking more closely, while they may start with a limited palette most artists add a few other colours for effect!
I am also dabbling with portraits so did these self portraits for my limited palette explorations.