Easy 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://wordpress.org/plugins/clean-and-simple-contact-form-by-meg-nicholas/