We demonstrate the generation and real-time observation of the vibrational wave packet of D-2(+) by using a sub-10-fs extreme UV high-harmonic pump pulse and a three-color probe laser pulse whose wavelength ranges from near-IR to vacuum UV. This multicolor pump-probe scheme can provide us with a powerful experimental tool for investigating a variety of wave packets evolving with a time scale of similar to 20 fs. (C) 2012 Optical Society of America