Different colour shading for boxes

Hey everyone,

First of all, fantastic little plug-in. Too easy to use!

Unfortunately I’m a bit OCD and one of my input boxes’ background colour is appearing in a different colour all together (white) to the others and it’s making me twitch. Do you know anything that could be causing this?

As you can see from the link, the ‘Best Contact Number’ field is a different shade and I for the life of me can’t figure it out.

Thanks for any help,
Pat

https://www.ads-software.com/extend/plugins/contact-form-7/