Sets the `Texture` object used to display the color picker's value slider.
Sets the Texture object used to display the color picker's value slider. The color picker's value slider displays a value gradient (and allows control of the color's value component) for whichever hue and saturation is selected in the color wheel. In the default UI's ColorPickerFrame, this part is found to the right of the color wheel.
This method does not allow changing the texture image displayed for the slider background; rather, it allows customization of the size and placement of the Texture object into which the game engine draws the color value gradient.
