Hue blend mode not working as expected

I have a photo that has a red area—almost magenta— that is supposed to be orange. On looking around the web, I found some tutorials about changing colors using the hue blend mode. But when I try it, it doesn't behave as I would expect.

Starting with the photo as Layer 1, I add a new layer, Layer 2. (Not an adjustment layer, just a new layer.) In the layer properties dialog box for layer 2, I set its blend mode to "hue." I then select the brush tool from the tool bar at left edge of window, and I click on the foreground color icon. This takes me to the color picker. I enter the RGB values for the desired shade of orange and click "OK."

So, at this point the correct shade of orange appears in the foreground color box. With Layer 2 selected,  I paint over the red areas with the orange foreground color selected. But rather than the selected shade of orange substituting for the deep red on Layer 1, the orange and red appear to add together, making a muddy brown That is darker than either the red or the orange alone.

So my question is: is this the expected behavior? Or am I missing something that is making the colors add together rather than substitute one for the other? If this is the expected behavior, I don't see how the hue blend mode could ever result in a lighter color.

Finally, if this is the expected behavior, what should I try next to change the hue of the deep red area to orange without changing the hue of the rest of the layer?

I'll be glad to post screenshots, but I don't know what screenshots would be helpful, so please tell me what you need.

Thanks.