Sentence:  On this mighty tide the black ships [...] are borne along to the town of St Ogg's, which shows its aged, fluted red roofs and the broad gables of its wharves between the low wooded hill and the river brink, <WSD>tinging</WSD> the water with a soft purple hue under the transient glance of this February sun. 
Meaning of the word marked with <WSD> tags:  To add a small amount of colour; to tint;  to add a small amount of some other thing.