You need to adjust the inline CSS(possibly a CSS option in the theme?).
/* input.TextField for WP-Email
input.textbox for WPG2 */
input.text,
input.textbox,
input.password,
input.file,
input.TextField,
textarea {
padding: 3px;
color: #000000;
border-top: solid 1px #000000;
border-left: solid 1px #000000;
border-right: solid 1px #000000;
border-bottom: solid 1px #000000;
background: url(http://retrochip123.com/wp-content/themes/atahualpa/images/outputbackgr.gif) top left no-repeat; }
The image referenced for the background(as far as i can tell) doesn't exist.
Two options.
1. Fix the image, or point it at another.
2. Remove the reference and just set a background colour.
Setting background colour(incase you don't know how), adjust the background line to read.
background: #fff;
Hope that helps.