For most materials the color does not matter persay, however there is are outcomes with certain color schemes that have allowed the child's mind to "get" the connections.
Geometry plane insets: the blue corresponds with the geometric solids in both primary and elementary (presuming you have blue solids...). Yellow opposes blue quite nicely as a background.
The map colors again don't really "matter" but why re-think the wheel? Each of the colors contrasts nicely with the ones next to it. Color-blindness combinations could be considered before re-thinking this color scheme..
Pink and brown are soft colors that coordinate well together - could you use another color for the pink tower and brown stair? Yes, but these soft colors are ideal for the age level (brand new, very young children need comfort); they coordinate well on a color circle (think art, aesthetics, beauty).
Red and blue are clearly opposing. (Red and purple - purple contains red; same with yellow/green; red/yellow or blue/yellow could work, however you're getting into brightness versus a darker shade - best to have the same shade in this work - the yellow/blue works for the geometric cabinet, darker shape, lighter background; it wouldn't work as well for the number rods, sound cylinders, and the like where we want an even surface, not negative/positive space).
|Can you find the spot where a cube is missing?|
Why not make everything in the sensorial area all-natural and have the child focus just on the concept at hand? Isn't that a Montessori concept - isolation of a property?
Except those classrooms with ONLY all-natural sensorial materials have materials that collect dust. They are not as attractive (we want to attract the child) because they do not oppose each other; when placing the tower pieces next to the stair pieces, there is no opposition of color in the different dimensions, no beauty. We are missing the development of aesthetics. And we need a certain amount of contrast within particular materials (anything that is currently 2-colored or more).
The natural knobbed cylinders are nice - and besides being a preparation for writing, they do have the child focusing solely on the dimension - but the children aren't putting those pieces with each other - they might later match them with the (colored) knobless cylinders; then the colors of the knobless indicate the set to which they belong and contrast nicely with the natural knobbed cylinders (sort of like matching the natural-based bells with the black and white bells - natural is for any of them, while a color is for a specific set).
When pairing natural grain to natural grain, the focus becomes on the pattern of the grain - rather than on the dimensions themselves. The lines in the grain actually detract the eye from the dimensions we are actually wanting to focus on....
In the end, what has been historically colored has strong aesthetic, color-blindness and practical purposes for being colored in the combinations utilized.
Buy the natural ones if they are cheaper (usually they are); then paint them! This way, you'll have extra of the right color/shade on hand for repairs when they chip (because they do chip - and that's great, because it's a sign they are being *used* - and opportunity to teach about care of the environment through gentility).