primary brights

16:53 Apr 20, 2013 

I think you may be missing the point of the source text here: it is not talking about specific colours, but rather, types of colours; hence the use of the plural 'eggshells' makes it clear we are not referring to a colour known as eggshell, but rather, colours generally in an eggshell range (basically, wishy-washy, rather pastel).

This is then contrasted with 'bright, primary colours' — not of course limited to just the 3 classic primaries, but other strong, saturated colours with a clear dominant; in non-technical fields, 'priamry' is often used in EN with this slightly wider and woollier meaning.
Likewise, 'berry' doesn't imply specifically 'red berry', but simply darker shades with a higher black component and lower saturation — these could be orange, red, purple, blue — admittedly, green berries may be slightly rarer (well, olives?); turquoise or yellow would be ruled out as in any case being light colours

So we are really talking here about light, pastel tones / saturated, bright colours / sombre shades.

21:21 Apr 19, 2013 

colour naming as used by paint manufacturers is a language of its own - a bit like wine tasting. If you don't have in front of you the actual colour chart of that paint manufacturer you are quite likely to end up nowhere near the intended meaning.
"primary brights" are not primary colours - extremely unlikely - wouldn't make for an orderly transition from "chalky eggshells" (roughly pale yellowish) to "berry colours" (reddish); more likely to mean "basic versions" of various bright colours.
Primary colours - just three of them? - that's ways too simplistic for paint manufacturers for home decoration.
You really need the colour chart to make sense of his ST.
If you a search on the Net, you'll find that "primary brights" is used in fashion to mean "couleurs vives unies" as opposed to "fabric with patterns", but all paints are "unies" anyway, so it's not much of a clue.