We have always been fascinated by colours. They evoke emotions, affect our mood and appear everywhere around us. Nevertheless, it was not until recently that Maxwell could explain what colour actually is - photons interacting with atoms. Thereby, we began to understand why certain metal complexes exhibited vivid and varying colours. Specifically, this project explored the colour variations in cobalt complexes. Three cobalt complexes were synthesized and analyzed with a spectrophotometer. Their chemical properties were similar, but not their colours. To explain the observed phenomena, ligand field theory was applied. By accounting for the orbital energy differences that the ligands give rise to and comparing standard values to those obtained, the different colours were understood.