Photoshop Frustration

I’ve been frustrated this morning by the way colour tables are edited in Photoshop. An indexed PNG being used as an OpenCV grabcut mask needed updating to match an image shown to the user in app. Once I had the new image I wanted to modify the colour table to reduce it to the three indexed coloured required by the algorithm. After getting annoyed with the seeming lack of the ability to quickly modify the table in Photoshop I saved the colour table, edited using Hex Fiend and within 1 minute had the new reduced colour table ready to use.