It states in the rules that a player has to play at least one card of the color of the round when declaring the color.
If you played all of your cards in the previous round and drew a wild card at the end of your last play do you
a) Play the wild card(s) in the new hand and declare any color?
or b) pass the lead on to the next player clockwise.
This is not covered in the rules.
As according the rule from Ivanhoe, a) is correct