Wildcard characters cannot be used with random input problem

[Jexxxxx]

What is the reason for this?
I can't use the wildcard color to input random words in forward words, but I can use the wildcard color to input random words in reverse words.

There is only one case that can be used in the forward word, that is, only color without any words, and just adding a space or comma after color will not work for random input words.