Header color?

[Riceburner]

I got a look at my headers yesterday and noticed they have turned a strange color. They are full stainless steel and usually go a 'goldy purple' color with heat, now I had to rework the front three pipes to get clearance for my huge sump. I used stainless, but it has gone blue 

 

Is this going to cause problems due to pipes expanding at different rates? How can I tell if it's the same stainless?

[Agno]

How much use have the headers had? Both before and after modifying the front 3 pipes.

 

 

[Riceburner]

Had one years use incl a few track days and about 4-6hrs since the mod. I did clean them before fitting after the mod, everywhere original has gone gold/purple except the newer pieces which have turned blue.

[luvemfast]

Colour would be an indication of temperature wouldn't it?

Blue clearly hotter than straw.

Have you changed anything mechanically? Mods will change exhaust temps and speed. If the colour is different on your mods to the headers, you've changed the scavenging effect.

It's really hard to tell from that photo though.

But I doubt the grade of stainless would have any dramatic affect.

[Riceburner]

Mechanically, I have got the new carbs. I had to re-shape the middle 1/3rd of the primaries on 1,2,3. The top/bottom 1/3rd of the primaries is still the original stainless and has colored normally (like 4,5,6), it's only these middle 'new' stainless bits that are going a very different blue color. I also made sure to keep them equal length.

 

I thought like you that is was heat, but then the top should be as hot or hotter than the middle of the primary. Strange huh?