what is best way to establish average rgb value for colour with noise ?

Hi,

created a circle selection and copied out a sample from the colour I wish to establish an average rgb value for, as its got subtle noise, so moving the pipette over it on 1 pixel sample sees rgb values altering a bit by a few units.

armed with this copy pasted sample to a new file, how do I turn it into a single uniform rgb value colour ?

If I gaussian blur it the edges start to encroach and centre goes pale. I have applied Gaussian blur a little but can still get varying values on 1 pixel sample although it has less visible 'noise'.

its only 15 pixels diameter. biggest sample I could take without getting spoilt parts with unwanted features.

Merlin