Here are some lightfast tests on random watercolour swatches that I've left to face the sun for 6 months. I'll probably do a proper scan at the one year mark.

The challenging part of this is actually thinking of a way to organise the swatches, and keeping track of the colours that I've already swatched out so that there are no repeats.

All the swatches below are labeled, but I'll only talk more about those that have faded.

White Nights Cadmium Yellow Medium PY35
White Nights Yellow Ochre PY1, PY43
White Nights Cadmium Red PR108

White Nights Carmine PR170
White Nights Blue PB15:6
White Nights Ultramarine PB29

Jackson's Art Magenta PV19
Jackson's Art Pyrrole Red PR254
Jackson's Art Alizarin Crimson PR83

PR83 is supposed to be a fugitive colour but I did not notice any fading for Jackson's Art Alizarin Crimson.

Jackson's Art Cadmium Yellow Light PY35
Jackson's Art Quinacridone Gold PR101, PR206, PY150
Jackson's Art Raw Sienna PBr7

Jackson's Art Viridian PG18, PG7
Jackson's Art Burnt Sienna PBr7
Jackson's Art Neutral Tint PBk7, PB60, PR209

Jackson's Art Phthalo Blue PB15
Jackson's Art Cerulean Blue PB35
Jackson's Art Ultramarine Deep PB29

Daniel Smith Red Jasper Genuine
Daniel Smith Napthamide Maroon PR171
White Nights Cadmium Lemon Yellow PY35

Nila Colori Genuine Lapis Lazuli
Daniel Smith Cascade Green PB15, PBr7
Daniel Smith Deep Ochre PY43

Genuine Lapis Lazuli from Nila Colori seems to have faded slightly. It's supposed to be a lightfast colour so it's surprising to see it fade. This will need to be checked six months later.

Nila Colori Burnt Umber PBr7
Nila Colori Maddery Garance Red NR9
Nila Colori Ercoland Red PR102

Nila Colori Maddery Garance Red has faded.

Nila Colori Burnt Sienna PR102
Nila Colori Maya Green
Nila Colori Raw Umber Earth PBr6

Nila Colori Weld Yellow NY2
Nila Colori Yellow Earth PY43
Nila Colori Yellow Ochre PY43

Nila Colori Weld Yellow has faded a lot. The original colour wasn't that intense to begin with.

Nila Colori Red Ochre PR102
Nila Colori Raw Sienna PY43

Nila Colori Cochineal Magenta NR4
Nila Colori Malachite PG39
Nila Colori Indigo NB1

Nila Colori Cochineal Magenta has faded.

Nila Colori Maya Blue
Nila Colori Ultramarine Blue PB29
Nila Colori Ultramarine Violet PB15

Mission Gold Rose Madder PR176
Mission Gold Crimson Lade PR202
Mission Gold Bright Opera PR122 BV10

Mission Gold Bright Opera is an almost fluorescent intense pink. After six months, it has faded into a more washed out, pastel looking like pink.

Mission Gold Red Violet PR122 PB2PV15
Mission Gold Bright Clear Violet PV3:2, PR122
Mission Gold Cerulean Blue PB15:3

Mission Gold Permanent Yellow Deep PY65
Mission Gold Permanent Yellow Orange PO73, PY65
Mission Gold Orange PO73, PY65

Mission Gold Vermilion PR112, PO73
Mission Gold Permanent Red PR112
Mission Gold Quinacridone Permanent Rose PV19

Mission Gold Cobalt Blue No1 PB29, PB15:3
Peacock Blue PB15:3, PG7
Mission Gold Ultramarine Deep PB29, PV15

Mission Gold Prussian Blue PB27
Mission Gold Indigo PB27, PB29, PBk7
Mission Gold Van Dyke Green PG7, PBr25

Mission Gold Viridian PG7
Mission Gold Hooker's Green PG36, Pbr25, PY150
Mission Gold Sap Green PG36, PY150

Mission Gold Olive Green PG36, PY150, PR112
Mission Gold Yellow Green PG36, PY3
Mission Gold Greenish Yellow PY150, PG16, PY65

Mission Gold Yellow Ochre No1 PY42, PY150
Mission Gold Burnt Umber Pbr7, PY65
Mission Gold Burnt Sienna PBr25, PR122, PY150

Mission Gold Light Red PY150, PBr25, PR112
Mission Gold Red Brown PBr25
Mission Gold Burnt Umber PBr7, PBr25, PY150

Mission Gold Van Dyke Brown PBr7
Mission Gold Sepia PBr7, PBk7
Mission Gold Permanent Yellow Light PY83, PY74

Shinhan HWC Yellow Ochre PY42
Shinhan HWC Vermilion Hue PO73, PR254, PY110
Shinhan HWC Crimson Lake PV19, PR177. PR122

Shinhan HWC Vermilion Hue has faded slightly.

Shinhan HWC Burnt Umber PBr7
Shinhan HWC Ivory Black PBk9
Shinhan HWC Permanent Yellow Light PY1

Shinhan PWC Peacock Blue PB15:3
Shinhan PWC Cerulean Blue PB35
Shinhan PWC Ultramarine Deep PB29

Maimeriblu Burnt Sienna PBr7
Shinhan HWC Cobalt Blue hue PB29, PB15
Shinhan HWC Prussion Blue PB27

PB27 can range from fugitive to lightfast. Shinhan HWC's version has faded slightly.

Shinhan HWC Permanent Green No 1 PY3, PY53, PG7
Shinhan HWC Viridian PG7
Shinhan HWC Burnt Sienna PBr7

Shinhan HWC Chinese White PW6
Kusakabe Permanent Yellow Light PY1
Kusakabe Yellow Ochre PY43

Kusakabe Rose Madder PR83
Kusakabe Prussian Blue PB27

PR83 is also know as Alizarin Crimson. Kusakabe's version of PR83 seems to fade more compared to the one from Jackson's Art. The original colour also differs from Jackson's Art's PR83.

Kusakabe Prussian Blue PB27 has also faded quite noticeably.

Maimeriblu Permanent Green Deep PY175, PG7
Maimeriblu Sky Blue PB35
Maimeriblu Ultramarine Light PB29

Maimeriblu Cobalt Blue Deep PB74
Maimeriblu Hooker's Green PG17
Maimeriblu Burnt Umber PBr7

Sennelier Sap Green PB29, PY153
Sennelier Burnt Umber PBr7
Sennelier Payne's Grey PV19, PB15:1, PBk7

Schmincke Transparent Yellow PY150
Schmincke Translucent Orange PO71
Schmincke Quinacridone Gold Hue PY150, PR101

Kusakabe Vermilion (Neo) PR4
Sennelier Primary Yellow PY74
Sennelier French Vermilion PR242

Kusakabe Vermilion (Neo) has faded slightly.

Sennelier French Ultramarine Blue PB29, PV15
Sennelier Cinerous Blue PB15:3, PW4
Sennelier Phthalo Green Light PG7, PY153

Kusakabe Ultramarine Light PB29
Kusakabe Viridian (Neo) PG7
Kusakabe Sap Green PG36, PY110

The yellow in Kusakabe Sap Green have faded.

Kusakabe Burnt Sienna PBr7
Kusakabe Burnt Umber PBr7
Kusakabe Ivory Black PBk6

Shinhan PWC Permanent Red PR209
Shinhan PWC Viridian Hue PG6
Shinhan PWC Cobalt Blue PB28

Shinhan PWC Permanent Violet PV3
Shinhan PWC Burnt Sienna PR101
Kusakabe Chinese White PW6

Shinhan PWC Permanent Violet PV3 has faded quite noticeably.

Maimeriblu Permanent Yellow Lemon PY175
Maimeriblu Golden Yellow PY183
Maimeriblu Pyrrole Red PR255

Maimeriblu Raw Sienna PBr7
Maimeriblu Permanent Orange PO64
Maimeriblu Primary Red PV19

Maimeriblu Permanent Orange PO64 have faded slightly.

Shinhan HWC Crimson Lake PR83
Shinhan HWC Vermilion Hue PO16
Shinhan PWC Cadmium Green Light PG7, PY35

Here's another version of PR83 which did not fade. The colour also looked different compared to the other PR83 shown earlier.

Shinhan PWC Prussion Blue PB27
Shinhan PWC Yellow Ochre PY42
Shinhan Burnt Umber PBr7

White Nights Green PG8
White Nights Burnt Umber PBr7
White Nights Umber PY43, PBr7, PBk7

White Nights Neutral Black PR187, PB15:1, PBk 7
Mission Gold Lemon Yellow PY3
Mission Gold Permanent Yellow Light PY154

Notes
Several colours from the Kusakabe watercolour set are fugitive.

Just because the name of the colour says it's permanent doesn't mean it's permanent or lightfast.

Shinhan PWC is the professional line and is suppose to be better than Shinhan HWC.