Standard HTML form controls. Enabled element borders are 4.5:1. Disabled elements are 3.0:1 All borders were 1 px.
Used Color Contrast Analyser (https://www.paciellogroup.com/resources/contrastanalyser/) on Windows and Macintosh.
Is there enough contrast difference between 4.5:1 for enabled controls and 3.0:1 for disabled controls, such that user with low vision can tell the difference between them?
NOTE:Firefox and IE do NOT allow styling of radio button or checkbox controls.