http://weavingmachinery.co.uk/webassist/themes/Weaving%20Machinery/css/default_styles.css
edit:
.productDetailWrapper .addToCart form input#WA_Store_Cart_1_Quantity_Add {
font-size:11px;
padding:5px;
width:40px;
}
to:
.productDetailWrapper .addToCart form input#WA_Store_Cart_1_Quantity_Add {
font-size:11px;
padding:5px;
width:40px;
color: #000000;
}