Red and blue16 Mar 2018 09:06
As you know -a general rule trades reported as blue if above the spreads mid price or as a sale in red if below the mid price.
For the morning opening sp the MMs choose to set the price based on the previous days mkt and any general mkt news/trends once and specific stock RNS.
Usally trading settles down after the initial opening.
Bear in mind their are a number of MMs for each stock,each with their own view of the price range want they based on the above hence the occasional large overal spread and price range shown.
Having said that on many occasions for numerous reasons such as a volatile fast moving market,delayed order filling,demand etc.,the sales /buys have the appearance of being incorrectly reported.