Image darkens when using 'Save for web & devices'

Ok, so I figured to add this information here in case it's helpful to others who may have had this issue happen to them, or if they happen to come across it. This is using Photoshop CS4, so I'm not sure if other version will do the same?

A few years ago on the IFX site this started happening to me, and it drove me crazy trying to figure out what was causing it. And last night it started happening once again, but I figured out the cause this time. - The attached examples below are of an image I've been playing around with for the past few days, which I'm also working up in grayscale. Until last night the saved images always looked as they did on my computer, but then I noticed the last one was darker than it should be. Not sure why or how I did this, but apparently the image mode was switched over to grayscale, and I had been working in RGB color mode up until then. Just not using colors yet. (this may have happened while fooling with another pic at the same time?) Either way, after some testing, this is indeed the cause of the saved image being darker than it should be. I don't know what causes this, or if there are setting to make the adjustment if needed. But if you happen to use the 'Save for web & devices, and you image is noticeably darker then it should be, simply check to make sure it's not in grayscale mode. If so, simply switch it over to RGB mode, and the saved image should be fine.

Hope this information is helpful.

First image, saved in RGB mode, and looks as it should.



Second image, saved in Grayscale mode, which has darkened the image more.

Thanks man.