The powder is called 'Sindoor'; the color is sometimes referred to as 'sindoori' in Hindi.

Helen, the 'dot' you refer to is called a 'bindi' (from Sanskrit 'bindu' which refers to a point or dot!) The 'bindi' isn't exclusive to the married female, though a red one is usually worn by them -- it has religious and cosmetic implications as well. The material of the 'bindi' can be derived from a variety of sources, turmeric being one of them. Others are 'sindoor' (for married women,) sandalwood paste (usually for religious purposes,) even the black pigment otherwise used as an eyeliner (espcially popular among younger girls/women.) In the present day, of course, one can see 'sticker bindis' made out of plastic, felt etc.

Turmeric is called 'haldi' in Hindi.