How to Invert Two Color Logos

Can't you use the invert command?

It's under image > adjust > invert, or CTRL+I on the keyboard

No sorry - that makes a negative.

Replace colour can be used, as TheRookie32 says, otherwise if it has nice crips edges, you can use the magic wand tool to select and delete the red,  then invert the selection, and use the bucket to fill in the white area. Turn off contiguous.

You can also do it with the channels.

Okay, this is weird, but this is how i did these two?- hope this is what you were looking for.-it was fun figuring it out.--
http://img2.freeimagehosting.net/uploads/9588888897.jpg
http://img2.freeimagehosting.net/uploads/407b852a7e.jpg


For the last fm image-
1. In photoshop i inverted the image and desaturated(it was a little grey so i brightened and contrasted until i had a black and white image of the last fm without jaggedy edges.--this is my first layer, white text, black backround(is what it looks like so far.)
2.Then i made a new layer and color dropped that red/magenta color from the website to the layer--filling it.
3. Then i went to the channels menu, added a channel, went back to my bottom black and white layer, selected it all, and pasted that into the new channel i made.  I also pasted this into a thrid layer ontop of the magenta color layer--then i put my mouse on this layer and press it.-keeping the focus on this layer.
4. Then comes the trick part, In the RGB Channle  menu i picked on the new channel i created, then shift cntrol picked the rgb layer at the same time This makes the layer mask. I went back out to the layers tab and pulldown add layer mask>reveal selection, which gives a perfect mask for the text.
5.That's it, perfect magenta text with the white background showing underneath.

For dictionary it's easier
1.i just color dropped the blue into a layer
2.copied the original image into another layer ontop of the blue layer, inverted it--yes it is all weird, then turned the layer options to linear dodge, that's it!

hope this helps.

Here is a variation on Todd’s method (now that Todd has done all of the leg work!)

1) Sample your two colors. One saved in foreground, the other in background.

2) Go to Image/Adjustments/Threshold.

The threshold dialogue box give you a slider with a preview checkbox. By changing the threshold point, you define a breaking point (threshold) at which to turn the artwork into 2-bit black and white.  Look for the setting that is most true to the original shape.

Here’s the advantage to using threshold. You have contrasting colors butting up against each other. To keep them from looking jaggy, they have been anti-aliased. This is done by blending the two colors over a small area so that from a distance, they look like a smooth transition.

The problem with anti-aliased colors is that you never quite know what to do with the colors that aren’t quite one color or the other. No matter which way you go, you will probably add distortion to the image.

With the threshold preview, you can decide just where you want the division to be.

3) Now that you have a black and white image, you are ready to drop in the colors. Choose the bucket tool (It’s hidden behind the gradient tool) Make sure anti-aliasing is checked and contiguous is unchecked. Click on the area you want to be the foreground color, swap background for foreground, then click on the remaining area.

4) Clean up as necessary.

5) Go show it to your mom!

Opps! I forgot the most important step! (silly me...) after you have a clean black and white from the threshold filter, invert to get a negative. It just wouldn't do to have an image in crisp black and white and then calmly use the fill tool to drop white into the black areas. (that’s what the undo command is for)

Total legend GreyNoMore, thats EXACTLY the sort of answer I was looking for, works like a charm for any 2-tone image and takes about 10 seconds.

Many thanks mate, full points to you!!!!

Thanks to TheRookie, I've never used the Color Replacement tool before but I couldn't get it to change the color of white or black!

Thanks go out to toddkeller, however I had a look at the images you inverted and the edges looked a bit rough. What I was really after aswell was a technique that would work for ANY two tone image and thats what GreyNoMore has provided.

Thanks to D_Brugge also, but again this technique produced very jagedy edges.

That's a good answer, i think the main difference is in that autocontrast, it does a better job than manually contrasting for sure, nice answer greynomore.
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