I looked through the mems and can't seem to find the answer, so I'm going to go ahead and post my question. I've been having problems with my channel mixer lately. Sometimes it will work, and sometimes it won't, and I can't figure out why. I try to add a channel mixer layer, and the box is all grayed out. It won't let me change the setting in channel mixer. I think it has something to do with the mode the image is in, but I'm not really sure. Please help! I use Photoshop CS 4 extended, and the images are usually in RGB/8bit. Thanks so much!