This was super complicated lol. I thought initially that it was the color in the corners that was the main color you were comparing.
I think that it was not easy to quickly understand who won the round by the player. Maybe showing a point counter when the cards are flipped over or stopping the game and waiting for the player to click a button to go to the next turn would be better for clarity. In general, having a number on the cards equal to the total card power level would help.