For a Great UX, Consider the Colour Blind

Among my deficiencies is colour blindness; I'm not at the far end of the scale, but I have the traditional problems with reds/greens/browns. As Steve Fenton said (almost word-for-word) on his blog Test Your Website For Colour Blindness Issues, if you are not testing your website for colour-blindness, you are being stupid. I couldn't agree more.

So it's frustrating that when logging in to a major UK financial website, I am confronted by these buttons:

The vast majority of the thousands of you reading this will be thinking I don't get it; the rest of us will be thinking why did they choose the same colour for the "Log in" and "Clear" buttons?
The colours of these buttons are shown here, as various types of colour vision deficient people would see them (taken from the Color Blind Spectrum):

Normal	Protanopia	Deutanopia	Tritanoptia
#339900	#958600	#a58600	#518f9a
#cc0000	#786c1e	#886900	#cc1600

My colour blindness is Protanopia; you can see how I perceive the green and red buttons, and the lack of contrast between them.

With that in mind, imagine my delight when I pointed my web browser at the home page of the offending web site and saw a link that says High contrast

It does what it says on the tin; click it and you get this

In my naivity, I expected that when I clicked on the link to take me to the login screen, that too would be in High contrast mode. I expected the Log in and Clear buttons to be highly contrasted. This is what I got:

*sigh*  So nearly a great UX, but so far from one.