1. Turn off Auto Focus
2. Press the WB button and select

and press the center of the multi-selector to register the custom white balance.
3. Hold the ColorRight over the front of the lens and press the shutter button.
4. Select a memory number and then press enter.
5. Turn auto-focus back on.
Be sure the number you select and the number shown on the display next to the set symbol are the same.
Repeat whenever you change locations or lighting.
For further details download User's Guide from this page.
Sony eSupport - DSLR-A700 - Manuals / Specs / Warranty
Turn to page 63 and follow the directions for custom white balance substituting the ColorRight for the "White Area."