Colour of radomes on aircraft

[Doc72]

Hello,

the colour of radomes is something that puzzles me when looking at cold war and modern military aircraft.

In the past, the majority of planes had black radomes. As far as I have understood, the usual explication is that paints that were at the same time sufficiently resistant to abrasion at high speeds and permeable to radar waves could only produced with certain pigments which happened to be black. Apparently technological progress later allowed for other colours as well and this is why black radomes are nowadays less common on military and civilian jets. The case of the F-16 fits well into this pattern: On very early F-16As the noses were black but this was soon changed as it compromised the otherwise grey camouflage.

However, much earlier Starfighters already rarely carried black radomes, at least most F-104Gs had light grey noses from the 1960s onwards (the CF-104 seems to be an exception). Early radar-equipped British jets sometimes had radomes left in their „natural“ yellowish glassfiber color (Meteor and Venoms, I think). This seemed to have vanished with higher air speeds. However, such radomes could still be seen on South African Buccaneers when they were delivered, while the RAF always (?) had the radomes on their Buccaneers painted in camouflage color to match the rest of the aircraft. On the Lightning radomes seem to be always dark green.

Nowadays, almost everything is grey in military aviation. Nevertheless, German Tornados still display black radomes although this contrasts starkly with the light bluish grey camouflage. There seems to be no Tornado-specific technical reason for this because British Tornados have grey noses (the Italian and Saudi ones, however, look black like the Germans). In the French Air Force, Mirage 2000Ns have black radomes while Mirage 2000Ds have camoflaged ones, although both jets are closely related. There are certainly much more examples like this.

Can anyone explain to me the technological and probably also financial reasons behind this? What determines the colors of radomes? I suppose the radar technology as well as the material of the radomes (which nowadays seem to be rather dyed than painted composites) is of some importance.

Thanks in advance

Ole