Backlight assembly and display apparatus

A backlight assembly, comprising:

• a light source;
• and
• at least one light-absorbing substance;
• wherein:
• the light source is configured to emit a white light, the white light comprising a first, a second, and a third primary color lights respectively corresponding to blue, red, and green;
• the at least one light-absorbing substance is disposed at a light-out side of the light source and configured to absorb light in at least one overlapping portion between spectra of two of the at least two primary color lights in the white light;
• the at least one light-absorbing substance comprises a first substance with absorption peaks of about 480 nm and 540 nm, comprising at least a cis-isomerized indigo dye and a second substance, with an absorption peak of 580 nm, comprising a trans-isomerized indigo dye to thereby reduce half-wave widths of the second and third primary color lights, such that half-wave widths of the first, second, and third primary color lights become all are reduced to be in a range of 20 nm 100 nm to thereby improve color purity of the backlight assembly.