1. A CMP planarizing pad adapted to planarize a microelectronic workpiece, comprising: a matrix adapted to support an abrasive, the matrix having a planar planarizing surface; a thermally responsive fluid in the matrix, the thermally responsive fluid being adapted to change color in response to a first temperature; and a second thermally responsive fluid in the matrix, the second thermally responsive fluid being adapted to generate a visible color change upon reaching a second temperature, the first temperature being correlated to a first planarizing condition and the second temperature being correlated to a different second planarizing condition.