a client of mine came up with a "fix", to access that manual entry field.
maybe this will help Kendo figure out why its borked.
1. right clicking on the hex code
2. Select all
3. Deleting current hex code
4. Typing in the new hex code
I deployed a work around to our sites, which just used an input box and a button to feed the input into the color picker (from outside of the color picker).
this of course is not an elegant solution.