Since Reeves gouache and Lefranc & Bourgeois gouache don't have lightfastness test results, I've been running some lightfastness tests on them since 2011.

Methodology

I would've liked to have had some Blue Wool test strips for direct comparison & analysis purposes, but haven't been able to find any in packages smaller than "several hundred dollars of equipment and meant for official test lab" quantities.

In the absence of official test strips, I went with the Unofficial but Very Empirical method.

• I painted gradients across divider lines and labeled every sample.
• One end of each gradient was solid pigment; the other was diluted with water to create as pale a wash as I could get, in order to determine whether pigments were more or less bleach-prone at specific concentrations.
• I cut my test strips in half. One half went into a dark spot; the other half got taped into my windows.
• I put my test strips in south-facing windows in my house in central Illinois. It has partial shade in the late afternoons but gets pretty direct sunlight most of the morning and definitely at noon.
• Single-glazed from 1936 = pretty much guaranteed not to have any UV protection built into them.

The test strips were installed in my windows in August 2011. Timed reports:

January 2012:

• So far they're generally holding up pretty well.
• The reds and peaches are (predictably) the ones with the most bleaching to date.

Not colorsafe enough for SCA purposes:

• The Reeves flesh tone in the window has lost most of the red to it and has turned into a paler beige-yellow.

Probably not colorsafe enough for SCA purposes:

• The Reeves crimson in the window is still noticeably in the red family, but it's definitely started to lose its red pigment and shade more toward purple-blue.
• The Lefranc & Bourgeois crimson is also starting to lose some of its redness. I still identify it as red, but I also have to note that most artists want their scrolls to be able to be displayed longer than 6 months, so we'll have to see what further sun-time does.

(6 months is too soon to label something as "definitely colorsafe," but the others are holding up better than the reds. I'll make another report at a year.)

September 2012 (updated October 2013 as noted):

NOT colorsafe enough for SCA purposes:

Reeves:

• The Reeves flesh tone in the window has almost completely vanished.
• The Reeves brilliant red has lost about half its intensity and the paler tint has vanished entirely.
• The Reeves crimson has shaded toward purple-blue and the tint has nearly vanished.
• The Reeves orange-red has shaded toward brown and portions of the tint have vanished.
• The Reeves violet has lost all the red in the mixture and is now a solid blue instead of purple.

LeFranc & Bourgeois:

• The Lefranc & Bourgeois orange and primary red have both lost the tint sections of the card, though the solid sections of the card are still in place and still color-consistent.
• Oct. 2013: While the Lemon Yellow was still passable in Sept. 2012, the additional year's time has sun bleached it notably more than the other survivors on its card.

Probably colorsafe enough for SCA purposes:

The following colors haven't had any noticeable fading at all over 2 years of direct sun exposure, when compared to their in-the-dark test patches. Since most scrolls won't be stored in direct southern-exposure sunlight and since a year's made no perceptible difference to them, I think they're probably colorfast enough, though I'll keep reporting in.

Reeves:

• Lemon yellow
• Medium yellow
• Blue lake
• Ultramarine
• Leaf green? (The tint has faded but is still visible; the color hasn't shifted)
• Emerald? (The tint has faded but is still visible; the color hasn't shifted)
• Dark green
• Yellow ochre
• Burnt sienna
• Burnt umber
• Grey
• Black

Lefranc & Bourgeois

• Primary yellow
• Violet (This is a color that didn't pass in the Reeves set, but it's both maintained its intensity and its color in Lefranc & Bourgeois)
• Ultramarine blue
• Emerald green
• Primary blue
• Burnt sienna
• Black
• Leaf green (This color has less noticeable fading than the Reeves set)