The blue font signifies any modifiable data at the lowest level cross-sections of dimensions.
The values in the blue font in the image below are examples of the cross-sections of child dimensions. These values can be changed and published back to Cube.
The Revenue and Income values appear in black font as they are parent dimensions and are not publishable. If these values were changed, they would not be included when publishing to Cube. Learn more about which values are excluded from publishes.