ho provato a vedere il report del validatore di css del W3C e questo è quanto:
codice:
Line : 6 (Level : 1) You have no color with your background-color : body 
Line : 10 (Level : 1) You have no color with your background-color : #header 
Line : 59 (Level : 1) You have no background-color with your color : #menu dt a 
Line : 59 (Level : 1) Same colors for color and background-color in two contexts #centre and #menu dt a 
Line : 59 (Level : 1) Same colors for color and background-color in two contexts #droite and #menu dt a 
Line : 59 (Level : 1) You have no background-color with your color : #menu dt a 
Line : 59 (Level : 1) Same colors for color and background-color in two contexts #droite and #menu dt a 
Line : 59 (Level : 1) Same colors for color and background-color in two contexts #centre and #menu dt a 
Line : 74 (Level : 1) You have no color with your background-color : #conteneur 
Line : 78 (Level : 1) You have no color with your background-color : #centre 
Line : 94 (Level : 1) You have no background-color with your color : .menugauchep 
Line : 94 (Level : 1) Same colors for color and background-color in two contexts #centre and .menugauchep 
Line : 94 (Level : 1) Same colors for color and background-color in two contexts #droite and .menugauchep 
Line : 101 (Level : 1) You have no background-color with your color : .menudroitp 
Line : 101 (Level : 1) Same colors for color and background-color in two contexts #centre and .menudroitp 
Line : 101 (Level : 1) Same colors for color and background-color in two contexts #droite and .menudroitp 
Line : 107 (Level : 1) Same colors for color and background-color in two contexts #header and .droit 
Line : 107 (Level : 1) Same colors for color and background-color in two contexts #conteneur and .droit 
Line : 107 (Level : 1) Same colors for color and background-color in two contexts #pied and .droit 
Line : 107 (Level : 1) Same colors for color and background-color in two contexts body and .droit 
Line : 107 (Level : 1) You have no background-color with your color : .droit 
Line : 113 (Level : 1) You have no color with your background-color : #droite 
Line : 123 (Level : 1) You have no color with your background-color : #pied 
Line : 141 (Level : 1) Same colors for color and background-color in two contexts body and .menuhaut a 
Line : 141 (Level : 1) Same colors for color and background-color in two contexts #conteneur and .menuhaut a 
Line : 141 (Level : 1) Same colors for color and background-color in two contexts #pied and .menuhaut a 
Line : 141 (Level : 1) Same colors for color and background-color in two contexts #header and .menuhaut a 
Line : 141 (Level : 1) You have no background-color with your color : .menuhaut a 
Line : 151 (Level : 1) Same colors for color and background-color in two contexts #centre and .menugauche 
Line : 151 (Level : 1) You have no background-color with your color : .menugauche 
Line : 151 (Level : 1) Same colors for color and background-color in two contexts #droite and .menugauche 
Line : 159 (Level : 1) Same colors for color and background-color in two contexts #header and .menugauche a 
Line : 159 (Level : 1) Same colors for color and background-color in two contexts body and .menugauche a 
Line : 159 (Level : 1) You have no background-color with your color : .menugauche a 
Line : 159 (Level : 1) Same colors for color and background-color in two contexts #pied and .menugauche a 
Line : 159 (Level : 1) Same colors for color and background-color in two contexts #conteneur and .menugauche a 
Line : 175 (Level : 1) You have no background-color with your color : .menudroit a 
Line : 175 (Level : 1) Same colors for color and background-color in two contexts body and .menudroit a 
Line : 175 (Level : 1) Same colors for color and background-color in two contexts #conteneur and .menudroit a 
Line : 175 (Level : 1) Same colors for color and background-color in two contexts #header and .menudroit a 
Line : 175 (Level : 1) Same colors for color and background-color in two contexts #pied and .menudroit a 
Line : 182 (Level : 1) Same colors for color and background-color in two contexts body and p 
Line : 182 (Level : 1) You have no background-color with your color : p 
Line : 182 (Level : 1) Same colors for color and background-color in two contexts #pied and p 
Line : 182 (Level : 1) Same colors for color and background-color in two contexts #conteneur and p 
Line : 182 (Level : 1) Same colors for color and background-color in two contexts #header and p 
Line : 191 (Level : 1) You have no background-color with your color : .footer 
Line : 191 (Level : 1) Same colors for color and background-color in two contexts #conteneur and .footer 
Line : 191 (Level : 1) Same colors for color and background-color in two contexts #pied and .footer 
Line : 191 (Level : 1) Same colors for color and background-color in two contexts #header and .footer 
Line : 191 (Level : 1) Same colors for color and background-color in two contexts body and .footer
volevo sapere se sono errori "gravi", visto che riguardano praticamente il fatto di aver scritto "background" e non background-color".