Beta-carotene is the orange colouring component found in carrots, and has vitamin A as a natural degradation product. Beta-carotene has a long, extended hydrocarbon skeleton with many conjugated pi bonds, leading to an absorption maximum in the visible region(blue light). Beta-carotene is therefore yellow-orange in colour.
Source: Organic Chemistry; Vollhardt, K.P.C and Schore, N.E.; Third Edition, 1998.