- In case of a tie, the Orange cap would be given to the one who has faced lesser balls to achieve this tied score. The Purple cap, in case of a tie at the top, is given to the one who has taken the wickets in the least amount of balls. This can be seen on the official IPL site Purple Cap standings 2013 (the link gets updated at the end of each game. Refer to the screenshot below for the standings as of 14th April where there is a tie) where Vinay Kumar (Royal Challengers Bangalore) and Kevon Cooper (Rajasthan Royals) have the same number of wickets but the purple cap is with Cooper as he has bowled 5 overs fewer than Kumar to get those 8 wickets.
Yes, the Orange cap owner who is fielding will be allowed to wear the orange cap till the end of the innings even if an opposition batsman has overtaken his runs. At the end of the innings, the batsman who has overtaken the said fielder's score will be presented with the orange cap and he can wear that when he comes out to field, assuming he still is the highest scorer. A scenario where a batsman wins the orange cap in the second innings of the game may not have the orange cap when this team runs out to field the next game.
Wiki says that the orange and purple caps are to worn only during fielding. There is no hard and fast rule about these caps while batting. Anyways, there are very few batsmen who bat with caps these days as they almost always come out with helmets, even to spinners. So, if the orange cap holder comes out to bat with a cap, I would assume it is his prerogative to either come out wearing his team cap or the orange/purple cap.
