For four representative clusters in our sample, [3.6]−[4.5] color vs. [4.5] magnitude diagrams of red IRAC sources located within 1′ of the BRCG position are shown (large black circles). We represent all sources within the field for comparison (small black dots). Arrows indicate a non-detections at 3.6 μm. The median color for sources with [4.5] < 22 is indicated by the solid horizontal and vertical dashed black lines, respectively. The ± 1 σ range in the mean color is indicated by the red shaded area. The values of the average surface density (σ), mean color, and its standard deviation are given in each legend for each source.