I found an interesting 9th century Chinese painting with two interesting features. Firstly, the Indian figures look sufficiently Indian (as opposed to really Chinese like they are often portrayed). The second is that Maudgalyāyana is quite fair compared to his companions. The Buddha of course is golden in colour.
Here Maudgalyāyana is on the left and Śāriputra is on the right with bodhisattvas on the far sides.
I imagine the artist read that Maudgalyāyana was fair skinned. Śāriputra also has really big eyes.