trying to change colour of text in search bar

Site URL: https://www.disordergallery.com

I am trying to change the colour of the text in my search bar from white to black. how would I do this?

Try adding to Design > Custom CSS

form.Header-search-form input.Header-search-form-input, form.Header-search-form input.Header-search-form-input::placeholder {
    color: white !important;
}