Alternate way to decide winnter when playing with both decks

First off we played a 3 player game, so we did what others have suggested in having no teams (everyone for themselves to get to 500) and just ignoring the "swap" cards. (But still keeping them in the deck in order to change trump color)

Here is an Example
P1: Yellow 8
P2: Yellow 3
P3: Yellow 8
--set the trick aside, whoever lead the last trick leads a new trick in yellow

P1: Yellow 7
P2: Yellow 5
P3: Yellow 7
--set this trick aside as well, player 1 must yet again lead with yellow

P1: Yellow 6
P2: Yellow 6
P3: Red 4
--again set the trick aside and player one must lead with yellow

P1: Yellow 5
P2: Yellow 3
P3: Blue 2
--Player 1 wins all the tricks, for a total of 40 points.

Sometimes only one tie breaker round is needed, we got as high as six, making the game get heated since so many points were up for grabs!

The only issue we had was if you can lead w/ trump on the tiebreaker hand if you run out of the original color, we decided no since you could manipulate your way into a tie to force a high score.

PS: For all the tie breaker rounds ignore flipping new trump cards.