ARGB1555
ARGB1555 is a 16‑bit color pixel format in which the most significant bit represents the alpha channel, followed by five bits each for red, green, and blue. The format is also called RGB1555 when the alpha component is omitted. Because only five bits per color component are stored, the maximum intensity for each is 31 instead of 255. The alpha value is either 0 (fully transparent) or 1 (fully opaque), so the format is mostly used where simple, binary transparency suffices, such as early handheld gaming consoles and mobile device displays.
The layout of the 16 bits is typically: A RRRRR GGGGG BBBBB. For example, the color white
Historical devices that exploited ARGB1555 include the Sharp X68000, the NEC PC‑Engine, and some early Sony
Compared with packed 16‑bit RGB565, ARGB1555 saves two bits to provide binary transparency, at the cost of