Colour of [Mn(NH3)6]Br2
The complex [Mn(NH3)6]Br2 is a coordination compound consisting of a central manganese ion surrounded by six ammonia ligands and two bromide ions. The color of a coordination compound is determined by the nature of the central metal ion and the ligands attached to it.

Factors influencing the color:
- Ligand field theory: The color of a coordination compound is determined by the energy difference between the d orbitals of the central metal ion.
- Crystal field splitting: The interaction between the metal ion and the ligands leads to splitting of the d orbitals.
- Absorption of light: The complex absorbs certain wavelengths of light, resulting in the appearance of a specific color.

Colour of [Mn(NH3)6]Br2:
- The color of [Mn(NH3)6]Br2 is pale pink or light purple.
- This color is due to the presence of the manganese ion in a specific oxidation state and the ammonia ligands surrounding it.
- The absorption of light in the visible spectrum by the complex gives rise to this color.
In conclusion, the color of [Mn(NH3)6]Br2 is pale pink or light purple, which is a result of the interaction between the manganese ion and the ligands in the complex.