If you want to do it manually, I suppose the easiest way is the following key sequence:

<Shift-Space> (which selects the entire row for the current cell. If the current selection takes in cells on more than one row, the selection is extended to all those rows.)

<Alt-H> (which selects the Home tab on the ribbon, if you're using Excel 2010. If you're using an earlier version, this sequence will have to change.)

<H> (to open the highlighting window)

Then click on the desired color.

There may be a keystroke that will let you select the color, but I'm not aware of it. And there might even be a way to create a keystroke that will do all of the above, without writing something in VBA. But I tend to use VBA a lot, so if there's another way I'm not sure what it might be.