zeroheight is simple to use, particularly for employees not experienced with design to collaborate with designers. The Design team can include color schemes (HEX, RGB), typography, logos, and other assets - as well as doing so using different languages and style sheets (CSS, JSON, etc.).

It provides a very clear structure for organizing design elements/brand guidelines. As well you don't need to be logged in to review the materials. So those who are not on the design team can still access materials, but can't change them.

Clean, easy and delightful to use, plenty of customization options, integrations with other tools, great support.