The 'Cornetto Trilogy' is the name given to 3 of Edgar Wright's comedic genre films starring frequent collaborators Simon Pegg and Nick Frost. This trilogy consists of 'Shaun of the Dead' (2004), 'Hot Fuzz' (2007) and 'The World's End' (2013). Although all 3 films are under different genres and have different cinematographers, the trilogy looks very similar. This can be mostly attributed to Wright's unique direction, editing and the fact that he and Simon Pegg wrote all 3 films, creating a consistent tone and feel throughout.
Another major contributor to this aesthetic is through Wright's use of similar locations, characters and colours. Firstly all the films are set in similar type areas. 'Hot Fuzz' and 'The World's End' are both set in rural villages (Sandford and Newton Haven) whilst "Shaun of the Dead' is set in a suburb, areas with similarities to villages. This use of similar settings in the trilogy allows the audience to understand that these films all come from the same director as they feel like they've been in these locations before. Similarly to this, all of the films have a pub location, furthering the similar but unique feel of all 3 films.
Many characters throughout the films have similar traits. For example; in 'Shaun of the Dead' and 'Hot Fuzz' Nick Frost plays very silly and goofy characters but in 'The World's End', Simon Pegg plays the more silly character. The use of similar character traits makes all the films in the trilogy feel even more similar despite their completely different stories, themes and genres. Furthermore many actors appear in many different roles throughout the films. Examples of this include Simon Pegg, Nick Frost, Martin Freeman and Bill Nighy. Wright's inclusion of these actors further makes his trilogy feel even more similar as we begin to further connect these recurring actors to the trilogy.
Wright's use of colour in the trilogy is another primary way of his particular aesthetic. In each film, there is a different colour 'Cornetto' (hence the name of the trilogy). In 'Shaun of the Dead', the 'Cornetto' is strawberry flavoured with red packaging which signifies the blood and gore in the film. In 'Hot Fuzz', it is an original 'Cornetto' with blue packaging, symbolising the police. Finally, the 'Cornetto' in 'The World's End' is mint-flavoured with green packaging, symbolising the science-fiction aspects of the film. The fact that this is recurring in every film allows Wright's aesthetics to further stand out as this is not common in many trilogies. Continuing with colour, in all of the films the colour is very similar; it is grey and dull. This is to give the aesthetic more realism as most places in real life are not that aesthetically pleasing. However 'Shaun of the Dead' and especially 'The World's End' use much more brighter colours as the stories that they tell are much more un-realistic than in 'Hot Fuzz', which looks much more grey than the others.
Although it doesn't have any real ideologies behind it, the aesthetic in Edgar Wright's 'Cornetto Trilogy' is very unique and instantly recognisable due to all the aspects discussed above.
This is a good over-view of Edgar Wright's aesthetic style and you highlight some key areas of his style. In the second paragraph you mention the 'similar areas' that the films are set in. Whilst they are similar they also represent different areas of England. This point could be expanded upon by researching the stereotypes used throughout the films.
I also challenge you to find the ideologies that are hidden within the films. They may not be obvious but they are there!