Set color of text in a formula

"1 -" + item('Brand of Competitors', 0) + " " + item('Model of Competitor', 0) + ", 2 -" + item('Brand of Competitors', 1) + " " + item('Model of Competitor', 1)

Hi, how do I set the color to red for the numbers "1 -" and "2 -" in the formula. The numbers continue to 30 in the complete formula. thanks