Final answer:
The color of the bar under the direct access knob settings indicates the level of water stress: blues for no stress, pinks and lavenders for potential stress, and salmon to brown for high stress and scarcity.
Step-by-step explanation:
The color of the bar under the direct access knob settings serves as an indicator of water stress levels in the given context. The blues represent areas with no predicted water stress, suggesting sufficient water availability for the production of crops without additional irrigation.
The colors ranging from pinks and lavenders signify regions that could experience water stress, where there might be a need for some irrigation to meet crop demands.
Furthermore, when you see salmon to brown colors, these indicate severe water scarcity, and thus, these areas might require substantial irrigation to support crop production. The variations within these colors provide a more detailed prediction as to the amount of irrigation that may be necessary.