Of several colours, all equally white, that will look whitest which is against the darkest background. And black will look intensest against the whitest background.
And red will look most vivid against the yellowest background; and the same is the case with all colours when surrounded by their strongest contrasts.
Every object devoid of colour in itself is more or less tinged by the colour [of the object] placed opposite. This may be seen by experience, inasmuch as any object which mirrors another assumes the colour of the object mirrored in it. And if the surface thus partially coloured is white the portion which has a red reflection will appear red, or any other colour, whether bright or dark.
Every opaque and colourless body assumes the hue of the colour reflected on it; as happens with a white wall.
That side of an object in light and shade which is towards the light transmits the images of its details more distinctly and immediately to the eye than the side which is in shadow.
The solar rays reflected on a square mirror will be thrown back to distant objects in a circular form.
Any white and opaque surface will be partially coloured by reflections from surrounding objects.
[Footnote 281. 282: The title line of these chapters is in the original simply _"pro"_, which may be an abbreviation for either _Propositione_ or _Prospettiva_--taking Prospettiva of course in its widest sense, as we often find it used in Leonardo's writings. The title _"pro"_ has here been understood to mean _Prospettiva_, in accordance with the suggestion afforded by page 10b of this same MS., where the first section is headed _Prospettiva_ in full (see No. 94), while the four following sections are headed merely _"pro"_ (see No. 85).]
WHAT PORTION OF A COLOURED SURFACE OUGHT IN REASON TO BE THE MOST INTENSE.
If _a_ is the light, and _b_ illuminated by it in a direct line, _c_, on which the light cannot fall, is lighted only by reflection from _b_ which, let us say, is red. Hence the light reflected from it, will be affected by the hue of the surface causing it and will tinge the surface _c_ with red. And if _c_ is also red you will see it much more intense than _b_; and if it were yellow you would see there a colour between yellow and red.