Changing entered text colors

Your theme stylesheet sets a white font color for all of the page elements. This includes the form inputs so you can't see the white text on the white input background.

You just need to target the form input fields and change the color. You can add this to the end of your theme stylesheet and you should be good to go,

body .gform_wrapper .gform_body .gform_fields .gfield input[type=text],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=email],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=url],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=tel],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=password],
body .gform_wrapper .gform_body .gform_fields .gfield select,
body .gform_wrapper .gform_body .gform_fields .gfield textarea {color:#000}

You can find more information on targeting form elements for CSS changes here.

http://www.gravityhelp.com/documentation/css-targeting-samples/

@robjr

This works fine in my test using Firebug.

body .gform_wrapper .gform_body .gform_fields .gfield input[type=text],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=email],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=url],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=tel],
body .gform_wrapper .gform_body .gform_fields .gfield input[type=password],
body .gform_wrapper .gform_body .gform_fields .gfield select,
body .gform_wrapper .gform_body .gform_fields .gfield textarea {color:#red; font-size:20px}

screenshot: http://grab.by/9v3M

The problem is that your stylesheet isn't being rendered by the browser completely.. it appears that a syntax error is preventing all of the rules from being applied.

validation results: http://j.mp/g60seC

Check out this section at the end of your custom.css

/* Styling for Workshops Master Page Listing*/
.galleriesThumb2 {
	margin: 30px 50px 50px 0px;
	.sideBySide, .sideBySide div {
		text-align: left;
		letter-spacing:0em;
	}

Notice that the ".galleriesThumb2" rule is not closed out properly before declaring the "sideBySide" rules. That's breaking everything in the CSS after that, your form rules included. Add a nice curly bracket after that rule and you should be in business.