Great idea! Importing EXR should be doable, exporting looks complicated. Would you also need to render back out to 32-bit EXR or would just importing be fine for your use cases?

Thanks for the answer. Blender's raw format is an EXR format. I only need to be able to import this format into the color.io software, to perform the color grading and finally be able to export it as a jpeg or png.