How do I change ONE colour of a placed image in Illustrator?

Question

I have gone through this forum and others, but have not found a way to achieve this successfully using the colour edit tool. Can you help?

I have a tiff file of a hand-drawn map, which I added colour to a long time ago in Photoshop (no longer have the .ps file).

This map is now in an illustrator file with other objects around it. I have decided I don't like the yellow of the roads, and would like them to have less of a green hue in them. I cannot saturate the whole image as this affects the perfect green of the parks, so need to change just the specific yellow to be a different yellow.

I have tried using the colour edit tool, but I simply cannot get it to change the colour. Yesterday I was able to open this up with the map selected but it did not want to change the yellow to any other colour I tried. Today I cannot seem to even open 'edit colours' with the map selected

Is this an issue as it's a Tiff file?

Really not sure how to change all of this yellow colour to be another and it's driving me a little nuts as I can see others are able to do it, but presume they are different types of files???

Answer 1

As the file you are working is a raster file made up out of pixels, Illustrator cannot edit it in any way except for opening it in Photoshop or, as Dodie Eslava points out, by first converting it into a vector by tracing. Do note that getting a high-fidelity trace of any pixel image is hard if not impossible.

For a change as elementary as changing a hue, there is of course some workarounds.

First, for ease of handling, place your file in Illustrator and lock it so you don't move it accidentally (Object > Lock > Selection). Then, you draw a shape over the roads. You can use any tool you like to create the shape. I used the Pen tool because it offers the most control, but be warned that it's hard to master. I gave the shape a thick magenta outline here to show what I've done: Then, change the shape's attributes so it has no stroke and an orange fill: Last comes the experimentation part. Find your Transparency palette (Window > Transparency) and start fiddling with the object's blend mode and opacity. You don't have full control over the colour this way, but quite a lot. It requires some experimentation to find out what blend modes and opacity settings work and which ones are too much.

I have two examples here, the first is Color Burn and 70%: And the second one is way subtler, with 40% Hard Light:

Lastly, clean up the extending edges, unlock the map and group map and object together.

Be warned though that blending modes behave differently depending on what colour mode you are using for your file: RGB or CMYK. If you switch modes later, the resulting effect may be drastically different. Choose a mode when starting out and stick to it. (Examples are in RGB)

Answer 2

because it is a flat file (jpeg/tiff) You must trace your file then re-color it. You can do this automatically or manually tracing of all the object. You can use Image trace or embed tool. Drag your file then trace it using image Trace + 3 Colors.

After that combine all same colors then recolor them.