A LUT (look-up table) remaps pixel colour values based on a defined XYZ matrix. This allows you to quickly replicate the appearance of various types of media, such as reproducing the cold, blue tone attributed to science fiction and horror movies.
The look up table is stored within a file previously exported from Affinity Photo or other applications (e.g., video packages). Alternatively, it can be inferred by comparing images.
Apply this adjustment via the Adjustment button on the Layers panel or via Layer > New Adjustment.
The following settings can be adjusted in the dialog: