Although not strictly part of the DTV platform architecture, the nature of the TV display mechanism (as opposed to a PC monitor) will affect the designs of your content – particularly colours, graphics and text.

YUV and colour display
European PAL TVs display pictures using YUV (as opposed to PC monitors which display in RGB). Y is pure luminance information, whilst U and V carry colour information. Y (luminance) is derived from the RGB signal, and consists of approximately 30%R + 59%G + 11%B. U and V are calculated as the difference between a colour and luminance: red-luminance (R-Y) and blue-luminance (B-Y).

When two very different/contrasting colours are put side by side the TV decoding and display mechanism has trouble making a clear distinction between one colour and the other. This can cause visual display issues, variously known as 'croma crawl', bloom, moire patterns and colour bleed.