a yellow square, indicating this line as the constituting ruler of the hexagram Six at the beginning means:

Pushing upward that meets with confidence
Brings great good fortune.

This situation at the beginning of ascent. Just as wood draws strength for its upward push from the root, which in itself is in the lowest place, so the power to rise comes from this low and obscure station. But there is a spiritual affinity with the rulers above, and this solidarity creates the confidence needed to accomplish something.