[3.6] – [4.5] vs. [5.8] – [8.0] color–color diagram for OriA-Fore 1 (orange dots, sources located within 20′  of the centroid of the overdensity, see Fig. 4), for known OMC2/3 members from Peterson & Megeath (2008) (green diamonds) and for the sample of ONC members from the COUP survey (blue squares). Dotted lines represent the boundary between class III and class I & II sources (shaded area) as defined in Allen et al. (2004).