What are some alternatives?
When comparing FontStruct and Color Palette Manager, you can also consider the following products
FontForge - Free (libre) font editor for Windows, Mac OS X and GNU+Linux
LOL Colors - Curated color palette inspiration.
FontLab VI - font creation and editing, including variable fonts and color fonts
Color Palette Generator - Enter the URL of an image and find its color palette
BirdFont - Birdfont is a free font editor which lets you create vector graphics and export TTF, OTF, EOT and...
Material Palette - Generate and export your Material Design color palette