Re: [Gimp-user] Problem with colorify & Hue-Saturation

[Ofnuts <ofnuts laposte net>]

On 04/08/2014 10:48 AM, OonaghG wrote:
> I have an RGB image (as set by Image-Mode) which is currently black & shades of
> grey.
> I want to alter this, in its entirety, so it is blue & shades of blue (a
> specific colour of blue).
>
> I have tried to vary Hue-Saturation and to colorify (manual says colorify should
> work on RGB) but although the tools come up on screen, when I adjust the colours
> in the dialog box my image does not change (I have preview turned on).

Method 1: Create a gradient from your darkest blue to your lightest 
blue, and use Colors/Map/Gradient map.

Method 2: Add a new layer above the grayscale one, bucket-fill it with 
your lightest blue, and set it to "multiply" mode.