Does this plug indicate too lean

[paulnobodyimportant]

Over the last 50 miles, since my re-lined and tuned Monza barrel has been running, I've been doing plug chops up to half throttle and the colour is always consistent with the photo's below. Its an AV266 atomiser with X2 on 2 clip.

Its slightly 4 stroking upto 1/2 throttle and bogs out if I turn on my choke. I get the sense that I could fine tune that out by putting the clip at the 1 and 1/2 position. However, thisd new plug does look on the lean side.

I do note that CamLam now recommend an AV268 atomiser, so I will try that next before I do any damage, but any feedback would be appreciated on the photos below.