Color change in palette is not effective in the image

Hi,
I want to change a color in the palette from blue to red. I’ve changed the color in the palette from blue to red but the blue pixels in the image are still there, while they should turn to red. As a result, I have blue pixels but no blue swatches in the palette. How can I change color in the palette and see the result “live”? Not with the replace color function, I need to edit the palette directly in RGB method, I know it works like this in Indexed, but indexed is limited…

Thank you

It has to be done in indexed mode if you want to change a range of color indices. You can always just create a palette based on your current image, then switch to indexed mode, make your changes, then switch back to RGB mode.
image

If you’re only changing one color, then Replace Color (Shift+R) is the best option.