Changing Text White background

[TLH9]

Does anyone know how to change the white background on the text screen (WHERE YOU TYPE) to an option of perhaps black, and typing white letters? I am thinking this is going to have to be an app that I download. I currently use Swiftkey, which I really like, and I have my dialogue background on black, but when I type in the text box it is white. The reason I am looking for this, is because, when I type at night, it's like turning on the lights. Any suggestions would be appreciated, thanks!