Clean and Simple Contact Form – Plugin

I′m really using version 4.6.1.

Having used this from – I don′t see where i′m able to change the color inside the text fields to a more readable color. Could anyone give me a hint?

I′d appreciate any hints.

Thanks in advance,

Sincerely,
Sam

https://www.ads-software.com/plugins/clean-and-simple-contact-form-by-meg-nicholas/