docs(color): content and image updates (#2020)

* docs(color): update the overview page's content and images

* docs(color): updates to usage page

* docs(color): update usage and accessibility pages

* docs(color): fix border around image

* docs(color): fix images

* docs(color): fix best practices images

* docs(color): fix punctuation

* docs(color): fix missing images

* docs(color): change "components" to "elements"

* docs(color): replace "components"

* docs(color): fix border radius of images