The cycle of love/light and light/love, or love and wisdom, or unity; associated with indigo ray.
Reference
1.1, 6.4-7, 6.23, 8.20, 12.28, 13.20, 14.19-21, 16.21-22, 25.9-10, 32.8-9, 32.11, 33.20, 36.1, 36.7-17, 36.22, 37.6, 41.4-6, 41.16, 43.14-15, 43.24-27, 45.4, 45.11, 48.6, 51.2, 52.3-7, 52.9, 57.33, 59.3, 60.13-16, 63.17, 64.6, 65.12, 66.6, 67.27, 68.10, 69.11, 70.6, 70.9-12, 75.32, 75.36, 77.24, 78.25, 81.16