The red square is an item used in The Eyes of Glouphrie and The Path of Glouphrie. It has a value of 4 in Oaknock's and Yewnock's machine, as calculated by multiplying the value of the shape's colour and the number of sides the shapes have:
Below is the value of each shape:
Colour
Value
Circle
Triangle
Square
Pentagon
Red
1
3
4
5
Orange
2
6
8
10
Yellow
3
9
12
15
Green
4
12
16
20
Blue
5
15
20
25
Indigo
6
18
24
30
Violet
7
21
28
35
Changes
Date
Changes
[[{{#explode:13 September 2023| |0}} {{#explode:13 September 2023| |1}}]] [[{{#explode:13 September 2023| |2}}]] (update)
The item's name was changed from "A red square" to "Red square".
Trivia
The item could not be received from Oaknock's Exchanger until an update on 25 November2020. One red square could be obtained from Brimstail at the start of the puzzle, after which he would never give out any more.