Pantone has a magenta ink, C=0, Y=0, M=100% K=0, used to print their Pantone Process Color System Guide. This ink matches the magenta color ink that I print with on my giclee printer. This is the same color on my Real Color Wheel that matches water colors, acrylics and oil paints. This color is Color Index Number PR:122. This color paint I first found perfect was from Liquitex, back when it was still called, by them, Acra Violet, it's been called Magenta now for a long time. Back then (1993) the only transparent yellow was from Old Holland as an oil paint. I guess the first acrylic transparent yellow paint was my own. I got the best Indian Yellow color match from a mural pigment dealer in Florence and made it.

I make watercolors with a transparent yellow from Spectra Colors Corp in New Jersey. This transparent yellow Azo pigment is called Tartrazine, PY100, and it didn't fade or turn brown after 6 months on my dashboard in the Lahaina sun. 'Lahaina' means the Land of the Burning Sun. I tubed another batch on 11-16-12.

Pencils and Pastels and crayons need pressure and lighter colors are not generally made with less pressure, it takes another pencil as pastels use another color. Magenta, PR:122 is Prismacolor's #995 called Mulberry. This is a full hue magenta that in watercolors would be thinned down to make pink. In pencil use #994 called Process Red as the lighter tint of magenta. Both make good darks with green (#909 Grass Green).

Prismacolor 1003 Spanish Orange is a dual-toned pencil. Light rubbing with is will give a lighter hue of yellow. It shows up more with an alcohol wash.

Prismacolor PC922 Poppy Red needs more red in it I think, cadmimum red light would be the natural pigment to use.

Prismacolor's PC903, called True Blue, pencil#31 has too much magenta in it, it's closer to cobalt blue hue. Maybe there is a better match in a larger set but for now I'm moving it to Cobalt Blue's spot, RCW#22. Let me explain my thoughts. Cyan is a transparent color, someday it will be dual-toned with a dark ultramarine blue like yellow is with brown. When using the opaque pencil cyan, it darkens with ultramarine blue, like the sky.

Comparing the darkest browns;
Prismacolors Dark Umber has more red in it than Dark Brown, which is on the yellow side. You needed both colors.
Sepia is the darkest brown in the set. It's raw umber hue, darker than the natural raw umber in oils.
Under a magnifying glass I laid in these colors, the media was soft enough to push around the laid color with the pencil, great for filling in holidays (sparkles). I don't think Prismacolor uses any natural pigments in their pencils.

Prismacolor has 3 dark browns, a magenta side brown RCW#10.10.5, a green side brown RCW#33.10.5 and a yellow side brown RCW#1.8.1. Normally Raw umber is a yellow-green side brown. Burnt umber is normally a red side brown. Prismacolor's Dark Brown is really a lighter burnt umber, a handy color.

Dick Blick has 2 dark browns, a red side and a yellow side. Those are the normal burnt umber and raw umber. Dick Blick calls them Bt Umber and Dk Brown.
Dick Blick also has a better cyan hue RCW#25 called Ice Blue, their darker mass-tone cyan RCW#25.7 is called Azure Blue.
Dick Blick has two different color Cobalt Blues, the dark has more magenta in it. In my opinion they don't even have a cobalt blue hue. They don't have a color named Ultramarine Blue in their 72 pencil set either. Dick Blick's Cobalt Blue Dark is my Ultramarine Blue RCW#19.