§3.1Δεῖ δὲ μὴ λανθάνειν τὸ πολυειδὲς καὶ τὸ ἄπειρον τῶν χρωμάτων, διὰ πόσα συμβαίνει γίνεσθαι.
We must not overlook the variety and infinity of colors, and through how many causes they come to be.
Εὑρήσομμεν γὰρ ἤτοι διὰ τὸ τῷ φωτὶ καὶ ταῖς σκιαῖς ἀνίσως καὶ ἀνωμάλως λαμβάνεσθαι· καὶ γὰρ αἱ σκιαὶ καὶ τὸ φῶς κατὰ τὸ μᾶλλον καὶ ἧττον πολὺ διαφέρουσιν αὑτῶν, ὥστε καὶ καθ᾽ αὑτὰς καὶ μετὰ τῶν χρωμάτων μιγνύμεναι ποιοῦσι μεταβολὰς χρωμάτων, ἢ τῷ τὰ κεραννύμενα τῷ πλήθει καὶ ταῖς δυνάμεσι διαφέρειν, ἢ τῷ λόγους ἔχειν μὴ τοὺς αὐτούς.
For we shall find that they arise either because they are received unequally and irregularly by light and shadows (for indeed shadows and light themselves differ greatly from each other in degrees of more and less, so that both by themselves and when mixed with other colors they produce changes of colors), or because the mixed elements differ in quantity and powers, or because they do not have the same proportions.
§3.2Πολλὰς γὰρ καὶ τὸ ἁλουργὲς ἔχει διαφορὰς καὶ τὸ φοινικιοῦν καὶ τὸ λευκὸν καὶ τῶν ἄλλων ἕκαστον καὶ κατὰ τὸ μᾶλλον καὶ ἧττον καὶ κατὰ τὴν πρὸς ἄλληλα μίξιν καὶ εἰλικρίνειαν αὐτῶν.
For purple, crimson, white, and each of the other colors have many differences, both in degrees of more and less, and in their mutual mixture and purity.
Ποιεῖ δὲ διαφορὰν καὶ τὸ λαμπρὸν ἢ στίλβον εἶναι τὸ μιγνύμενον ἢ τοὐναντίον αὐχμηρὸν καὶ ἀλαμπές.
It also makes a difference whether the mixed element is bright or lustrous, or on the contrary, dry and lusterless.
§3.3Ἔστι δὲ τὸ στίλβον οὐκ ἄλλο τι ἢ συνέχεια φωτὸς καὶ πυκνότης.
And luster is nothing other than continuity and density of light.
Τὸ γὰρ χρυσοειδὲς γίνεται, ὅταν τὸ ξανθὸν καὶ τὸ ἡλιῶδες πυκνωθὲν ἰσχυρῶς στίλβῃ.
For the golden color arises when yellow and sun-like light are strongly condensed and shine.
Διὸ καὶ οἱ τῶν περιστερῶν τράχηλοι καὶ τῶν ὑδάτων οἱ σταλαγμοὶ φαίνονται χρυσοειδεῖς τοῦ φωτὸς ἀνακλωμένου.
Therefore also the necks of doves and the drops of water appear golden when the light is reflected.
§3.4Ἔστι δὲ ἃ λειούμενα τρίψει καὶ δυνάμεσί τισιν ἀλλοίας ἴσχει καὶ ποικίλας χρόας, ὥσπερ καὶ ὁ ἄργυρος παρατριβόμενος καὶ χρυσὸς καὶ χαλκὸς καὶ σίδηρος.
There are also some things which, when smoothed by friction and by certain forces, assume different and diverse colors, just as do silver, gold, bronze, and iron when rubbed.
§3.5Καί τινα γένη λίθων διαφόρους ποιεῖ χρόας, καθάπερ καὶ. . . μέλαιναι γὰρ οὖσαι λευκὰς γράφουσι γραμμάς, διὰ τὸ πάντων τῶν τοιούτων τὰς μὲν ἐξ ἀρχῆς συστάσεις ἐκ μικρῶν εἶναι μορίων καὶ πυκνῶν καὶ μελάνων, ὑπὸ δὲ τῆς ἐν τῇ γενέσει βαφῆς ἁπάντων τῶν πόρων κεχρωσμένων δι᾽ ὧν διελήλυθεν αὐτῶν ἡ βαφή, ἄλλην ἐσχηκέναι τὴν τοῦ χρώματος φαντασίαν.
And certain kinds of stones produce different colors, just as also... for being black they draw white lines, because the original compositions of all such things consist of small, dense, and black particles, but due to the dyeing in their generation, all the pores through which their dye has passed being colored, they have assumed another appearance of color.
§3.6Ὁ δ᾽ ἀποτριβόμενος ἀπ᾽ αὐτῶν οὐκέτι γίνεται χρυσοειδὴς οὐδὲ χαλκοειδὴς οὐδ᾽ ἄλλην οὐδεμίαν τοιαύτην ἔχων χροιάν, ἀλλὰ πάντως μέλας, διὰ τὸ τοὺς μὲν πόρους παρατριβομένων αὐτῶν ἀναρρήγνυσθαι, δι᾽ ὧν ἡ βαφὴ διελήλυθε, φύσει δὲ καὶ τῶν αὐτῶν εἶναι.
But what is rubbed off from them is no longer golden or bronze-colored, nor has it any other such color, but is entirely black, because when they are rubbed, the pores through which the dye had passed are broken open, and they are by nature made of the same original material.
§3.7Τοῦ γὰρ προτέρου χρώματος οὐκέτι ὄντος ἡμῖν φανεροῦ παρὰ τὸ διασπᾶσθαι τὴν βαφήν, τὸ κατὰ φύσιν ὑπάρχον αὐτοῖς χρῶμα ὁρῶμεν· διὸ καὶ πάντα φαίνεται μέλανα.
For since the former color is no longer visible to us because the dye is disrupted, we see the color that belongs to them by nature; therefore everything appears black.
Ἐν δὲ τῷ παρατρίβεσθαι πρὸς ὁμαλὲς καὶ λεῖον ἕκαστον τούτων, καθάπερ καὶ πρὸς τὰς βασάνους, ἀποβάλλοντα ἀπολαμβάνει πάλιν τὴν χρόαν ἐν τῇ συνάψει καὶ συνεχείᾳ, τὸ τῆς βαφῆς διαφαινόμενον.
But when each of these is rubbed against an even and smooth surface, just as against touchstones, although shedding particles, it recovers its color again in contact and continuity, namely, the color of the dye shining through.
§3.8Ἐπὶ δὲ τῶν καυστῶν καὶ διαλυομένων καὶ τηκομένων ἐν τῷ πυρὶ ταῦτα πλείστας ἔχει χρόας, ὅσων ὁ καπνός ἐστι λεπτὸς καὶ ἀεροειδὴς καὶ τὰ χρώματα σκιώδη, ὥσπερ ὅ τε ἀπὸ τοῦ θείου καὶ τῶν ἰωμένων χαλκείων, καὶ ὅσα ἐστὶ πυκνὰ καὶ λεῖα, καθάπερ ὁ ἄργυρος.
In the case of things that are combustible, dissolvable, and fusible in fire, those of which the smoke is subtle and misty and the colors shaded, like the smoke from sulfur and corroded copper vessels, and those which are dense and smooth, like silver, have the greatest variety of colors.