The root chakra (just above your taint) is generally associated with the color red. Heart chakra is associated with green.

Meditation is such a broad description, anything from a moment of focused attention to sitting for hours muttering a mantra.

I haven't heard anyone talk of "growing" chakras, and I'm very much in that world, they aren't like muscles. You would grow your awareness of your chakras.

If you consider taking a moment to be aware of the sensations, emotions and images in the center of your chest to be "meditation," I'm not sure how you could accomplish your goal. Otherwise.. do that.

I like to take a moment when I see something particularly beautiful- sun sparkling on water, sunsets/sunrises, a striking vista, the moon on a clear night, and "breathe" it into my heart chakra.