his illusion is a doubleand thus reversed after-image, sometimes called contrast reversal

Though sometimes it may appear hopeless to find equal light intensities in pa1111and painting, in color pa.pers, or in our surroundings, we have found chatnawre occ;isionally provides an opportunity to see them on cumulus cloudsagainst blue sky.When rhcse clouds, of1e11lined up in horizontal groups,:tppcar gleami11g white in their upper part in full sunlight,separated from and rising ag71insta distant deep blue,1hcn underneath they show gi·ey tones as shaded white.These shades merge, or even hinge, wid1 the samebut here very close blue. \'Jhy very close? This grey isof die same light imensity as the neighboring blue below.Thu~. the boundaries between grey and blue vanish,and we do not sec where clouds end and where sky begins.With such clouds, this is best observed with the sun at our backs

However, the additional ill .f ' us1onary colorso ten are hard lo defu:ie ::islo their hue.They often ap . . . 1. pca1 ,ts s iaclow un one sid . .and as J1ght reflected I . c of the boundaryon t ie Other side

Additional experiments with light colors on light groundsand dark colors on dark grounds prove that the light of a groundsubtracts in the same way that its hue does.

In the first exercise it was learned that the more differentthe grounds, the stronger is their changing influence.It has been seen that color differences are caused by 2 factors:by hue and by light, and in most ca~es by both at me

he fact that one and the same color can perform many different rolesis well known and is consciously applied.

As "gentlemen prefer blondes," so everyone has prefe1·ence for certain colorsand prejudices against others. This applies to color combinations as well.It seems good that we are of different tastes.As it is with people in our daily life, so it is with color.

we study gradation by producing so-called grey s[cps, grey scales,grey ladders. These demonsr.rate a gradual stepping up or down betweenwhite and black, between lighter and darker

Whites rarely appear white but usually look greenish.This makes color slides oE Mondrian paintings unbearable

Vir.hin the pairs there is no equal light intensitybecause the conclusive question to be expected Crom a class is:arc there eqL1al light values within these couples?The answer is No

However, it is still true that only a minority can distinguishthe lighter from the darke1· within close intervalswhen obscured by contrasting hues or by different color intensities.

magine in front of us 3 pots containing water, from le[t to right:WARM LUKEWARM COLO·when the hands are clipped first into the outer containersone feels -- experiences • -. • c1·rr '• •• peH.e, vcs •• ~ 1 erent temperatures:~ (at left)Then dipping both handsinto the middle container,one perceives again2 different tern pera tu res,this time, however,in reversed order(at left)~··~ (at right)(at rig-ht) COLDthough the water is neither of these temperatures, but of another, namelyLUKEWARM

Colors present themselves in conLinuou~ llux, constantly rclllted tochanging neighbors and changing cond1uons

We are able to hear a single tone. .n !most never (1.h<1tis without special d..:vices) see a smglc coloruUl WC a , 'unconnected and unrelated to other colors

In writing," knowledge of spelling has nothing to do with an understandingof poetry

wordsconsisting of a ital letters present the most ditficult reading

his notion has proved to be wrong, because in reading we do not readletters but words, words as a whole, as a "word picture."This was discovered in psychology, particularly in Gestalt psychology.Ophthalmology has disclosed that the more the letters are differentiatedfrom each Other, the easier is the reading

Second, the nomenclature of color is most inadequate.

visual memor'. is very poorin comparison wHh our auditory memory.

Even when a certain color is specified which all listeners have seeninnumerable times•· such as the red o[ the Coca-Cola signs which isthe same red ;tll over the country-· they will still think ofmany different reds

-5,~ein~-here im~Jlie! Sch~11e1~(as in Wcltansd1a1111ng)and is coupled111th fantasy, w11;h1magmat1on.

1 his is parnllel to fhc rccog·nition that no theory ofc:0111 ..l •· d. . ' • pos1t10n by itselfc,1 s to the producuon of music:, or of ,irt.