What is the colour of oxygen in solid state ?

The colour of the solid iodine is

Generally transition elements form coloured salts due to the presence of unpaired electrons, Which of the following compounds will be coloured in solid state ?

Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in the solid state ?

What is the hybrid state of BeCl_2 in solid and vapour state?

Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid state -

Generally transition elements from coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid state?