Left panel: Optical V − R vs. R − I two-color diagram of V1184 Tau in different epochs. The solid green line represents the main sequence, while green dashed and dotted lines are the reddening vectors by Rieke & Lebofsky (1985) and Cardelli et al. (1989), respectively. Different A_V are indicated with open squares and labeled. The extinction vector is applied to the colors of a G5-type star. Blue dots show, the states in which V< 17 mag, red filled dots those with 17 ≤ V ≤ 18 mag, and red open dots those with V> 18 mag, respectively. Right panel: as in the left panel for the near-infrared J − H vs. H − K two-color diagram. Blue dots are the points with H< 11.5 mag and red dots those with H ≥ 11.5 mag. The yellow square indicates the colors of the photospheric temperature (5700 K), while black solid curves are the combinations of two blackbodies, one at 5700 K and the second with temperatures between 1000 K and 2000 K. The ratio of the two emitting areas is labeled, and the iso-surface curves are depicted with black-dashed lines.