The Symbology interface in ArcMap is great for applying multiple symbols to different values. However, it is a bit less obvious when you want to apply a change to multiple different symbols without changing the unique colors. For example, applying an offset shadow to many lines with different colors, as shown in the images below.
To apply shadows in batch to lines with different colors using Unique Values symbology, use the following steps:
- Bring the feature class into ArcMap.
- Double-click on the layer in the Table of Contents.
- Click Categories > Unique values and choose the desired Value Field.
- Click Add All Values and uncheck <all other values>.
- Click Symbol at the top left of the values list > Properties for All Symbols.
- Click Edit Symbol on the right.
- At the top of the Symbol Property Editor, choose Type: Cartographic Line Symbol.
- Set the width as desired.
- On the left-hand side, under Layers, click + to add a new layer and increase the width to match the other line.
- Click the down arrow under the Layers section on the left to be sure the second line is at the bottom of the list of symbol layers.
- Go to the Line Properties tab and increase or decrease the offset - this creates the shadow. Click OK twice.
- Apply unique colors to the lines by clicking the Color Ramp drop-down above the top right of the value table. Choose a ramp with separated color blocks with a variety of colors.
This applies shadows to multiple different colored lines. If you need to change each individual line color, double-click the line and change the color using the palette to the right, and click OK.