I think the problem may be with the way Acrobat is displaying the black. Do you have Acrobat Pro? if yes, when you check the Output Preview is there only black in that blend? Depending on the Output Intent in Acrobat the colors on screen may differ. Wich Creative Suite color setting did you use in Bridge?
Mybad (I think)... I re-exported w/o any conversion (i.e., "as-is") and black came across fine. It was converting a solid black to a cymk black, hence the hue change (I guess?).
Thanks for pointers though.
I think the problem is myself, and not knowing how to use the InD gradient tool. When I defined a swash gradient color (white>black) and applied it to a shape, it worked fine. Previously I was using the gradient feather tool and applying it to a pre-colorized shape and was then getting the shift. Seems to be working fine now. Thanks all for suggestions. The older I get the more I have to learn (relearn?).
Have had this problem in multiple adobe programs before and it's due to using different colour settings.
You want to make sure you're always working with the same colour format whether it be vector objects or graphics.
For example in Color Picker
With the slider at very bottom, and cursor selection bottom left. You'll notice the slider will reposition itself to try and best match the colour you are trying to generate based on the color format you have selected.
CMYK black = HSB:211,0,0 / RGB: 0,0,0 / CMYK: 75,68,67,90
RGB black = HSB:344,11,0 / RGB: 0,0,0 / CMYK: 75,68,67,90
This is because the colour conversion is not 100% accurate because different colour formats are designed to display colours in different mediums. CMYK is for print (ink), RGB is for electronic display (light). The colour spectrum for each format is also different which means you can get colours that are really close in each format, but never 100% the same, even when they look the same.
Think of the Color Picker kind of like trying to line up the continents of the world on top of each other and match them up precisely. It's impossible because each continent is a different size and shape, although what the Color Picker does is essentially separate each continent into smaller pieces and put the similar peices on top of each other. Sorry to be all metiphorical but it's the easiest way I could think to explain it.
The color/swatch that the InDesign Color Picker creates depends on the field your cursor is in, not the view mode you've chosen. So I can type in any CMYK build and if my cursor is in a CMYK field, my color values will be saved unchanged. Here my build is 0|0|0|100 and I get a 0|0|0|100 CMYK swatch from the picker—the picker displays an Add CMYK Swatch button:
If I move the cursor over to one of the RGB fields the picker displays an Add RGB Swatch and I get an RGB swatch that is a color managed conversion of 0|0|0|100 CMYK to RGB :
If I click on a radio button, the CMYK values change to a color managed conversion from the current space view color to CMYK. Here I'm in the Lab view and the conversion from Lab black to CMYK is 86|85|79|100. The resulting conversion numbers depend on the document's color profiles, in this case my profile is Fogra27 so I don't get your 75|68|69|90 conversion from RGB 0|0|0 black