Taking a picture with a nikon D50 the picture is bright colors?

Bright florescent colors

Leave it in automatic mode and it should handle everything itself. If the area is dark and the camera wants to use the flash, place a white kleenex in front of the flash to diffuse it. If the fluorescent colours are self illuminating, then you will need a tripod and use the aperture control mode. Before doing this, read the manual and practise the method. You might need to go with shutter speed control rather than aperture control, but in both cases, read the manual (available on-line) and practise.