It depends on your printer how to change the color to red. If you want to have your modifiers print red you would change the color code in the print template right before the {ORDER TAGS}. For example:
Kitchen Orders Template
…
[ORDERS]
<L00>- {QUANTITY} {NAME}
<XCT>29,40,78,2,0,48,50
{ORDER TAGS}
<XCT>29,40,78,2,0,48,49