For those that don’t know, gradient mapping is an easy way to recolor existing materials to a completely different color palette by assigning the brightness value of a given pixel in an existing texture to a given color. Unlike the current method of recoloring materials (which just overlays a flat color over an existing greyscale image with not-too-great results), gradient mapping can let you implement multiple different colors in an existing material (including making parts of the material lighter or darker), allowing for much greater flexibility. Additionally, due to its flexibility, it may improve condo performance by reducing the need for custom canvas materials.
To my knowledge, this is also fairly easy to implement shader-wise, although generating the gradient map itself without having the user use an external image editor may be more complicated (if desired).
Example wood texture with gradient maps shown: