Updated Rgb16Color object API (markdown)

Rgb16Color-object-API.md

@@ -132,7 +132,7 @@ This will blend between four colors by the amount defined by 2d weighting values
 
 ## Operators
 ### uint8_t operator[](size_t idx)
-The index operator allows accessing the R, G, and B properties using an index.  There are both read only and read write versions.
+The index operator allows accessing the R, G, and B properties using an index.  There is only read only versions.
 ```
    uint8_t green = color[1];
 ```