He must assume that particular colour or form which is beneficial for the particular object which he tries to achieve. A king who can put on various forms succeeds in achieving even the most subtile objects.
यस्मिन्नर्थे हितं यत् स्यात् तद्वर्ण रूपमादिशेत्। बहुरूपस्य राज्ञो हि सूक्ष्मोऽप्यर्थो न सीदति॥