From the 1920s onward, Japanese projectiles had the following colors:

Armor Piercing shells (tekkôdan) were painted overall white with a small red band in the middle of the shell body.  If the burster was loaded then the nose was painted green.  If the base fuze was installed then the green tip was painted red.  Shells with dye had a band the same color as the dye just after the red band.  The type numbers (such as "91" for Type 91) were painted on the windshield.

Common or HE shells (Tsûjôdan) were painted a brown-maroon color with a yellow band in the middle of the body.  Shells with base fuzes had green or maroon noses while those with nose fuzes had white noses.  See illustration above.

Exercise/Training shells (Enshûdan) had a black body.  If equipped with a nose fuze, then the nose was white, otherwise the nose was yellow.

Illumination or Star shells without parachutes (Seidan before 1938 or Shômeidan A after 1938) had a bluish-grey body with a white nose fuze and a yellow band in the middle of the body.

Illumination shells with parachutes (Shômeidan B) had a red body with a white nose fuze.

Incendiary shells (Shôi ryûsandan and Sankaidan) had a red body with a white nose fuze.

Shrapnel shells (Ryûsandan) had a grey body with a white nose fuze.

Smoke shells (endan) were painted orange overall.

Target shells (Mokuhyôdan) had a green body with a white nose.

Tracer shells (Eiryôdan or Eikôdan) were painted red overall.