In Uno, can you play a Wild Draw 4 Card drawn as a penalty, if you have a card the same colour as the draw pile?
Official Rules

"Official rules" do vary slightly from site to site, however all seem to agree (including the rules on Wikipedia) that being on the receiving end of a Draw Two or Wild Draw Four forces the player to draw 2/4 cards and forfeit their turn, therefore Player 2 is not allowed to use either card, and play continues to the next player after Player 2.

Under the official rules you are only allowed to immediately play drawn cards when, on your turn you choose to draw a card, and the card you have drawn is playable.

House rules

Otherwise there is a common house rule regarding not ending your turn after receiving a Draw Two and/or Wild Draw Four.

If playing with this house rule Player 2 must play the yellow card - if they were to play the Wild Draw Four they could be challenged by Player 1, and end up drawing more cards as a penalty for playing a Wild Draw Four while they have a card in hand that matches the current colour.