Tetraminos

This is more or less luck based. A color strike is a row that is completely filled with only one color. The easiest way to do this is at the start of the Endless mode. Restart the round if you don't get several pieces of the same color in a row. Try to get a 4 row high "wall" as soon as possible and stack the different colored ones on top of it to get them out of the way. Leave a 1 block wide gap and use a 4 stone piece to clear all 4 rows at the same time.