Change the color of font on form

Site URL: https://aardvark-chrysalis-jbhs.squarespace.com/

I can't seem to figure out how to change the font color which is currently white on my form. The words display; "name", "email", "subject", etc. but I don't want a red background to make them display. I need a white background but of course makes the letters disappear. I tried using "inspect" to pinpoint those words but that didn't help. I don't know how to use custom CSS on Squarespace but know enough HTML and CSS to figure that out once I know where I add the custom CSS. Thanks. 

yay! Thank you! So I had to type in "colors" in the search bar because I didn't see it in the listing. I was actually excited about looking more into the custom CSS feature and have played around with it and managed to change the color of something with help from "Inspect" but then the color didn't stay so I don't know if that feature is buggy or it's just me. 

inspect element won't change things except you locally to test how something will look