ACES intends to provide a universal base for a colour-managed workflow, replacing individual bespoke systems, to allow for accurate interchange between organisations as well as within, and for archival purposes.
ACES makes use of two important core concepts, “display-referred content” and “scene-referred content”. Before your content enters an ACES pipeline, generally, it is “scene-referred”. Once it has left the ACES pipeline, generally, it is “display-referred”.
Content which is produced by a camera or by a 3D renderer is “scene-referred”; that is, the values stored in the image are interchangeable only with other images from that camera or renderer using the same settings.
By contrast, “display-referred” content has a direct relationship between the values stored in the image and the expected colour and intensity of the image when displayed on a calibrated display.
As a user of imaging software outside of a colour-managed workflow, there are some unintuitive aspects of using a colour-managed workflow. The ACES pipeline is designed to bring your content from designated input or intermediate formats, such as ARRI LogC, Canon CLog3, or ACEScg to designated display output formats such as sRGB, rec2020 or P3-DCI. While ACES provides transforms for bringing output content back into ACES space, and these transforms are often necessary (e.g. if you have a camera that outputs rec709 content), the intention is that the pipeline is end-to-end with a single output stage. Bringing display-referred content into ACES and putting it through a pipeline again is not transparent.
Visit this link for a helpful ACES colourspace to RGB converter.