Orange in boiler flame

[nishnish]

Hi,
I've noticed quite a bit of orange in the flame of my 240 RSF:

http://galatea.salford.ac.uk/aix502/07032010011.mp4

Download the great free video player, VLC, if you can't play that:

http://www.videolan.org/vlc/

The CH and DHW are good and hot.
I have a working carbon monoxide detector just above the boiler. Which tests ok and has never triggered.
I was wondering if that amount or orange is an indicator of some fault?
Would that be dirty jets?
I did have a GSR guy perform a service in Jan. He said he'd tweaked the flame and it was now burning better than before.
I was having a DHW over temp tripout issue at the time (since fixed) and he said that it might need a new gas valve to fix that, but not to improve the flame, which he reckoned was fine when he left.
Thanks.

 

[Andygasman2010]

it doesn't look too bad. ideally it wants to be a sharp blue flame, maybe a little orange sometimes. when it's floppy yellow is when you need to worry. a performance test should tell you, the guy who serviced it should have done one. You want a ratio of less than 0.0040

 

[Gasguru]

Give the side of the boiler light thump with your hand...then you'll see orange flames...it's just rust particles. Yellow tipped flames are however a problem. Despite its age your burner is in fact likely to be far safer than a modern Band A boiler.

 

[nishnish]

Thanks guys.
So orange ain't bad, just yellow.

Does the orange indicate any failing? Poor efficiency? Or simply a bit of dirt?