What causes the vibrant colors characteristic of many transition metal compounds?
Answer
Subtle shifts in electronic structure due to d electron behavior upon bonding with ligands
The characteristic colors arise from electronic transitions involving the d electrons of the metal ion after it forms a coordination complex with surrounding ligands, which alters their energy levels.

#Videos
Why do Transition Metals Form Coloured Compounds? - YouTube
Related Questions
What causes the vibrant colors characteristic of many transition metal compounds?What term describes the five d orbitals when a transition metal ion is isolated and gaseous?In an octahedral complex, how do the five d orbitals typically split?What condition must typically be met for a transition metal ion to produce color via d-d transitions?If a complex absorbs strongly in the lower energy (red-orange) region of the visible spectrum, what color will be perceived?What determines the magnitude of the energy gap ($\Delta$) induced in a transition metal complex?Which type of ligand causes a larger energy gap ($\Delta$)?How does the magnitude of splitting ($\Delta_t$) in tetrahedral complexes compare to octahedral complexes ($\Delta_o$)?Why are colors resulting from typical d-d electronic transitions often pale or washed-out?What causes the intense, opaque colors seen in compounds like potassium permanganate ($ ext{KMnO}_4$)?