Have to be careful with the genus Pingasa in HK. There are four species, all pretty similar. (P. chloroides, P. rubimontana, P. rubicaunda & P. ruginaria)
All the photos above are of Pingasa ruginaria, though 旱季型 is very worn and more typical of its dry season form. Of the four spp., only P. ruginaria has the substantial yellow basal suffusion on the ventral surface.