This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.
From http://css.researchkitchen.de/validation.html a { border: 1px solid c85 } a { border: 1px solid 123456 } a { border: 1px solid 8D2828 } all three declarations are invalid, but only the last one is reported as such.
Fixed in today's patch, online version will be up soon at http://qa-dev.w3.org:8001/css-validator/