Colour Hue is what makes a colour look red, green, blue, yellow etc. Many different shades of a colour will have either the same or very similar hue values.
By selecting an area of a pattern and swapping colours of one hue value for a different hue, it is possible to change a red rose to a yellow rose and maintain all the shading.
To use the hue change, you select the area of interest and then a stitch of the colour hue you want to change. You can then select what range of hues will be changed by typing in a percentage tolerance. Finally, select a colour with the new hue value you want to change to. Every stitch within the selected hue range will be given the new colour hue. The other parameters of the colour will remain unchanged thus preserving the shading. Finally, the colours are matched to available thread colours.