The Image > Mode > RGB Color command converts the active image into a true-color image. All of the supplementary image information, e.g., image calibration and drawing objects, will be retained in this conversion.
Time stacks
In time stacks, all of the frames will be converted. The result of a conversion carried out with the Image > Mode > RGB Color command will again be a time stack. The frames in the converted time stack are true-color images.
8-bit gray-value images
When you convert an 8-bit gray-value image this does not alter the image's appearance. So, the resulting image does not contain any color information. You should, however note, that the size of the file will increase considerably, since the image then contains three color channels. The color channels are thereby exactly equal, since a gray value results when the red, green and blue values are all the same.
You can use color tables to have gray-value images displayed in color on your monitor. When the conversion is made, the colored gray-value image will be converted into a 24-bit true-color image. After the conversion, you can no longer alter the color table, it has then become a component of the image.
Multi-layer image
With multi-layer images, you only convert the active image layer. In the Layers tool window, the active image layer is indicated by a check 
. You can also use this tool window to change the active image layer.
See also
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