Posted this bug here: http://stackoverflow.com/questions/39412559/kendo-ui-colorpicker-validation-bug-for-hex-colors Below the copy: The Kendo UI color picker control allows entering HEX value manually. But is has a bug: if you try to enter #123XXX, you will see then #112233 The reason is the Kendo UI color picker parses the first part of the color #123 (which is a correct short form) and ignores the rest XXX symbols (which are not valid HEX symbols) If you try another case: enter #XXX123, you will see the validation error (HEX value will be highlighted with red). I need to validate correctly both cases and show the validation error. But I can not find a way to add custom validation to this control. Question: do you know how to work around this bug and make Kendo UI color picker control fail on validating values like #123XXX, #ADCXYZ, #19BW00 instead of cutting off the last 3 symbols and interpret the first 3 as a short HEX form?