I was recently exploring the ShapeSheet formulas available in Visio that affect colors, and I decided that I needed to make a shape that I can change the fill color, tint, shade and tone of dynamically. This allows me to copy the formulas from a Shape Data row value for pasting into a ShapeSheet cell.
The top part of the shape displays the chosen fill color, and the RGB and HSL formulas can be copied from the Shape Data window.
There are three horizontal bands below the main rectangle that each have a yellow control handle which slides to the left and right. This control handle will change the value for the TINT(…), SHADE(…) and TONE(…) functions.
The shape also contains copious hyperlinks to the ShapeSheet function definitions and many right mouse menu actions to set the fill color to one of the standard, theme or color map options.
Links to Microsoft MSDN pages:
Download the Visio document with the Color Formulas master shape on from here : VisioColorFormulas.vsdx
Whilst thinking about this, I realised that my good friend, and fellow Visio MVP, John Goldsmith, created an excellent Visio color picker shape. See Creating a color picker in visio