When I edit existing pdf file,and change spot color of separation color space to another(from one pantone color to another ,for example) ,I can't see the difference(colors are changed only if I change it to None or All).Is application using tint transform and alternate color space by default,except in case when color is set to None or All? I read in pdf reference that only if output device can't recognize color ,tint transform is used,then how it recognize one pantone color and other not?
I really do not understand the question. The color space typically would not change. Are you opening the PDF in Illustrator? Are you selecting an element in Pantone A and changing it to Pantone B? The change should be obvious unless it is so subtle, you can't see the change on your monitor. But, the color space should be retained in whatever scenario you're discussing. Color space usually refers to either RGB or CMYK in Illustrator.