Top: red, green, and blue image (F444W, F200W, and F150W) of an example extended red source (white circle of radius ﹩0\mathop{.}\limits^{^{\prime\prime} }3﹩). The field size is ﹩3\mathop{.}\limits^{^{\prime\prime} }2﹩. The 870 μm ALMA image of the same area is shown in the inset in the lower left corner. The galaxy is strongly detected with ALMA at both 870 μm and 1.2 mm. Bottom: same as the top panel, but for an example compact red source, which is an LRD. Here the inset is from the DUALZ image, and there is no ALMA detection.