Color Adjustments and PowerPoint 2007

I am having trouble understanding how the color adjustments described in the Open XML for a PowerPoint presentation are applied in PowerPoint.

Take a look at the Technic theme in PowerPoint 2007.

In this theme, the moderate background fill style is a linear gradient. The base color is background2, which is (R=59,G=59,B=59). There are three stops in the gradient.

I am using the color picker UI in PowerPoint to look at the actual color of the stops and then examining the Open XML that describes the color adjustments for each stop. Here is what I get.

Stop 1. Actual = (R=36,G=36,B=36). Shade = 0.4, Saturation Modulation = 1.5

Stop 2. Actual =  (R=45,G=45,B=45). Shade = 0.6, Saturation Modulation = 1.5

Stop 3 Actual = (R=125, G=125, B=125). Tint = 0.83, Saturation Modulation = 2.0

There are a couple of odd things here.

1) According to my calculations, after converting the base color to the HSL space, the saturation value is 0. So I do not see why the adjustments have saturation modulations. Multiplying by zero has no effect. I checked with the online calculator at http://www.serennu.com/colour/colourcalculator.php and it also returns a saturation value of 0 for the base color. Should the saturation value for the base color here (R=59,G=59,B=59) be non-zero?

2) From the ECMA specifaction sections on Shade and Tint.

Shade - "This element specifies a darker version of its input color. A 10% shade is 10% of the input color combined with 90% black."
Tint - "This element specifies a lighter version of its input color. A 10% tint is 10% of the input color combined with 90% white."

For the first stop if I apply a shade of 0.4 to the base color I get (R=23,G=23,B=23) not (R=36,G=36,B=36). For the second stop, applying a shade of 0.6 to the base color I get (R=35,G=35,B=35), not (R=45,G=45,B=45). On the 3rd stop, applying a tint of 0.83 to the base color I get (R=92,G=92,B=92) not (R=125, G=125, B=125).

Does anybody have any insights on this?

Thanks!

I think the problem you're having is that the color modifications have to be applied in a specific order. In this case, you apply the tint/shade adjustments first, then perform any HSL modifications before converting them back to RGB for your use. (I ran into this with other documents I've looked at.)

Hope this helps!
fwdev

I ran into the same problem with Tint and Shade. I've applied them in the right order, but it still doesn't work. The Ecma docs have almost no valuable information on this subject - has anyone figured out a standard way to do the color transformations?

Answer at: http://social.msdn.microsoft.com/Forums/en-US/oxmlsdk/thread/f6d26f2c-114f-4a0d-8bca-a27442aec4d0/#697a93fd-4a35-42f0-ae3f-1d261a853067