The color for each point or symbol in a post map can be defined in the worksheet using a color column.  Define a color for each point in the worksheet using the color name or an RGB or RGBA color classification in an empty column.  Then follow the steps below to assign the color column to the post map.

1. Add a new column to your data worksheet containing the color names.
   1. Click File | Open in Worksheet, select your data worksheet and click Open. Or, open the data file in Excel.
   2. Populate the column by specifying the colors either by their name, by RGB, or RGBA color classification.
      1. The RGBA classification stands for Red, Green, Blue and Alpha (opacity) and the values can range from 0 to 255. 
      2. For example, you can enter either: Sky Blue, R105 G5 B105 or R105 G5 B105 A135
      3. If you already have columns of data for R, G and B respectively, you can use the CONTCATENATE function in Excel to combine them into one. For example, if the R value is in column D, the G in column E, and the B in column F, you could use: =CONCATENATE("R",D2, " ", "G",E2," ", "B", F2)

      4. The color names that you can use in the worksheet can be found in the color palette.

         
         Move the cursor over the colors and the color name
         is displayed at the top of the color palette.

   3. When finished, click File | Save or File | Save as. 
      
      
2. Create a Post map with your data sheet and apply the colors from the column: 
   1. Click Home | New Map | Post (or click File | Open) to create a new map, or add to an existing map by selecting that Map and clicking Home | Add to Map | Layer | Post. 
   2. Click the Post layer in the Contents window to select it.
   3. Click the Symbol tab in the Properties window.
   4. In the Symbol Color section, click the current value in the Color column field and select the appropriate worksheet column.
   5. Click the current value in the Color method field and select Explicit color names.

Surfer: Properties window showing symbol properties and resulting Post Map.

Additional articles you may be interested in include:

• What colors can I use in the data file for the color column for my Surfer post map?
• Can I indicate the symbols I want on my Surfer post map using the symbol index?
• Can I set the color or opacity of symbols in a Surfer post map to be based on a Z value?

Updated March, 2022