Hi Nicolas,
Thank you for your suggestion, i have created new characteristic and assign to product, system displays full set of new characteristic values correctly
And after i tried simulate this, i have found root cause;
If a characteristic already assigned to a product, modify that characteristic's values from characteristic menu will not take effect.
Even i tried to un-assign and reassign, system will not refresh for the new value.
To solve this i need to un-assign the existing "color" characteristic, assign newly created "size" characteristic, remove "size" characteristic and reassign "color" characteristic, done, system refresh for new value