I'm using Fireworks for graphical drawing, and I have this bitmap image that contains some greys that I wish to change it to red, however if I use the Hue/Saturation on it, it does not change colour.
What is the best method to change grey to red?
the very definition of gray is that its lacking any hue. If there is no hue, there's no way to adjust saturation.
That said, most image editing software has a checkbox in the hue adjustment dialogue labeled 'colorize' that will do exactly as you want...it will give the gray a hue of your preference.