Color change blocked

Alright this is a bit bizzare. But today I’ve been experiencing a bit of a problem regarding changing one particular color, be it with Shift + R or right click eraser. The color is #b37d32 and it’s the only color i cannot change. I reseted the PC once, fixed it but the problem came up pretty quickly again.

Is there a way to lock a certain color and I did that and simply do not know it?

Thanks.

that’s strange… can you erase the pixels with eraser tool? if so, are you sure your brush isn’t in shading mode?

ps. i consider the fact shading brush mode and custom brushes ignore ‘paint with background colour’ when it’s either mask (shading mode) or completely (custom brush) as quite an issue.

I could erase it yes, but that’s not what i wanted to do. I could change other colors on the same layer so it’s not either brush or layer thing i think. I did a workaround of making palette from sprite, then deleting the CURSED color from palette and index the picture.