Custom colormaps or color gradients can be added or deleted to the Presets list in Surfer via the Colormap Editor. Follow these steps to edit the presets list:

1. Open the Colormap Editor in Surfer
2. Either design your colormap by editing the colormap nodes, or click Load to load an existing CLR file
3. Click the Add button in the Presets section to add the new colormap into the presets list
4. Click the Edit button.
   1. In the Edit Presets List dialog, you can drag and drop the preset colormaps to rearrange them in the list. 
   2. Rename any of the presets by selecting it and clicking the Rename button. 
   3. You can also load new CLR files directly into the presets list by clicking the Load button.

These changes will be automatically saved.

Surfer 16.2 and earlier

In Surfer 16.2 and earlier, there is not a way in the user interface to change the order of the items in this list, or to add your own colormaps, however, you can do this by editing the Gradient.ini file that ships with Surfer. The Gradient.ini file is located in C:\Users\<username>\AppData\Roaming\Golden Software\Surfer <version>.

To rearrange the colormaps in the Presets list:

1. Open the Gradient.ini file in a text editor, like Notepad++.
2. Select all the lines of data for a particular colormap that you want to move. For example, the example below selects the Rainbow colormap information:
   
3. Click Edit | Cut.
4. Delete the empty line and then place your cursor at the beginning of the line you want this colormap to begin.
5. Press ENTER to add a new, empty line, and then place your cursor on that line. This example will put the Rainbow colormap between the GrayScale and ChromaDepth colormaps:
   
6. Click Edit | Paste to paste in the information.
   
7. Click File | Save and resave the file.
8. Restart Surfer and the colormap presets will be in the new order.

To add a new colormap preset:

1. Open the Gradient.ini file in a text editor, like Notepad++.
2. Put your cursor at the beginning of the line you want the new color to be on and press ENTER.
3. Put your cursor in the empty line and enter the colormap information. This includes the colormap name (containing no spaces), a 0 and the number of color nodes. This is followed by the information for each color node, starting with a number between 0 and 1 (which determines the color node location, in increasing order), then the RGB component values for that color node (integers from 0 to 255). More information is found in the Format and Notes sections at the top of the Gradient.ini file.
   
4. If this information is hard to create manually, you can create the colormap you want in the Colormap dialog of the user interface, and click the Save button to save it to a CLR file. Open the CLR file in Notepad++ and copy the colormap from the CLR file into the Gradient.ini file. You will need to make sure the header information is correct, and then divide the node positions by 100, since CLR files save the node positions in percent (from 0 to 100).
   
5. Click File | Save and resave the Gradient.ini file.
6. Restart Surfer and the new preset will be included in the drop down menu.
   

Updated December 2021