Can the color of the label be changed without changing the color of the element?
If you have a case where a user wants the color of a catchment to remain the default color, but have the label to be a different color, such as black, there is no direct way of doing this. By design, the color of the label is associated with the element color. This can help to differentiate different element labels and annotations. For instance, if the label for a catchment and the catchment set as the outflow node is the same, it may be difficult to ascertain which annotations belong to which element at first glance. By having the color for the annotations match the element color, it will be easier to quickly see which annotations below to which elements.
If you want to set the colors of the annotations to be different from the element color, you can try the following steps. This example uses catchments as an example, specifically to change the label color from the default of green to black.
First, open Element Symbology (View > Element Symbology) and double-click "Catchment" to view the properties. Change the default color to black and set the transparency value to a smaller value, such as 20%.
Note: Setting Transparency to zero will make is so the borders between catchments will not be visible. If the catchments are not touching, this will be fine. However, if you need to visually differentiate the borders of the catchments, you should use a non-zero value for Transparency. Setting this to 20% will allow the label to appear to be black. A higher value will make the label appear to be gray in color.
With this done, create a new Color Coding item for the catchment. Set the Field Name to "Area (User Defined)" or "Scaled Area", whichever you are using for your model. Calculate the full range to make certain you know the largest area. On the right side of the color coding dialog, in the column for "Value <=", enter a value larger than the largest area in your model and set the color to the color you want the catchment to appear in the drawing. Then click "Apply" and "OK".
Back in the drawing, the catchment and the label will be changed to reflect the color coding. Now go to Tools > Options and select the Drawing tab. Uncheck the item "Color element annotations" and click "OK". The color of the label will now be black while the catchment will be colored.
Note: This workaround will not work if other color coding is being used.
If this workaround is not suitable, the other option would be to use the tools in MicroStation or AutoCAD to change the color of the label. You can try this with the program in that platform (StormCAD for MicroStation, for instance) or export the drawing to a DXF file by going to File > Export > DXF and open the DXF in one of these platforms.