Separate your sliced vegetables into piles by color: red, orange, yellow, green, violet.
Add your red vegetables to a medium bowl. Add 1 tablespoon of the olive oil, a dash of salt, a dash of pepper, and a dash of garlic powder. Mix well then transfer to create your first row on the baking sheet. Repeat with each additional color.
Once each color is on the sheet, bake for 20 minutes or until roasted. Turn once at about 10 minutes to ensure even roasting.
For crispier veggies use one vegetable for each color and spread them out more on the sheet pan.