The article you reference provide VBA code you can learn from. In the routine they are changing font size with the following:
objShape.TextFrame.TextRange.Font.Size = “16"
To change the color of text, that is also a property of Font. Below is an example you could use to change the color to Blue.
objShape.TextFrame.TextRange.Font.ColorIndex = wdBlue
You can do a web search on Word VBA Font.ColorIndex Enumeration and get a listing of all the color values.