What is the color of Fe³⁺(aqs) ion?

The correct option is Yellow.

In aqueous solution, iron(III) ions typically exist as the hexaaquairon(III) complex ion, represented as:
$${\left[\mathrm{Fe}{\left(H_{2}O\right)}_6\right]}^{3+}$$

While the pure hexaaquairon(III) ion itself displays a very pale violet color, it readily undergoes hydrolysis in water. This hydrolysis reaction produces hydroxo complex species such as:
$${\left[\mathrm{Fe}{\left(H_{2}O\right)}_5\right(\mathrm{OH}\left)\right]}^{2+}$$ These hydrolyzed species are strongly colored and impart a distinct yellow or yellow-brown appearance to the aqueous solution. Therefore, the observed color of Fe³⁺(aq) in practical chemistry applications is yellow.