Knowing that the chemistry of lanthanoids is dominated by its (+3) oxidation state, which of the following statement is incorrect?

Because of large size of the Ln(III) ions the bonding in its compound is predominantly ionic in character. The ionic sizes of Ln(III) decrease in general with increasing atomic number. Ln(III) compounds are generally colourless. Ln(III) hydroxides are mainly basic.

Ln(III) compounds are generally colourless.

$Ln(III)$ compounds are coloured due to the $f-f$ transitions in the lanthanoids but the colour is fainter as compared to the $d-d$ transitions in transition metals.