Diode colour code ?

[N_Cook]

Did any company have a convention of putting different colour sleeving on
axial diodes instead of coloured bands ?
Doesn't matter in the present case as any old 1N4005 etc would do , but for
future reference.
All over black enamelled or black glass with no markings and blue sleeve on
anode lead and red on cathode lead, so not going with red to positive for
forward current transfer.
Size etc oes not agree with 1N602 , 1N206 , 602, 206 not found,
1N1206,1N1602, 1N2206 not found, 1N2602

 

[Allodoxaphobia]

Did any company have a convention of putting different colour sleeving on
axial diodes instead of coloured bands ?
All over black enamelled or black glass with no markings and blue sleeve on
anode lead and red on cathode lead, so not going with red to positive for
forward current transfer.

??? If I understand you: The cathode end is marked with red?
Seems normal to me -- as the cathode end yields positive voltage when
used as a rectifier. And being a rectifier is what a diode is...

Jonesy