When using an unmanaged raster catalog, it uses a default renderer. Changing the renderer on the Symbology tab > Available does not necessarily make it use that renderer.
The way to make an unmanaged raster catalog use a specific renderer is to remove all other types of rendering.
- Right-click on the raster catalog in the Table of Contents and select Properties to open the Layer Properties dialog box.
- Select the Symbology tab.
- Highlight the renderer type under Available to be removed and click the Remove button. Repeat this for all renderer types that are not to be used.
- If the desired renderer is not listed under the Available dialog box, add it by clicking the Add button.