Nope. They both support the same colourspaces and pixel formats. Since the pixel data is transmitted digitally without compression, it is lossless between the frame buffer and the display. This is not true for VGA.
There are a few things for which you should be aware though:
1. DisplayPort can carry audio, just like HDMI
2. DisplayPort transmitters can be passively adapted to work with single-link DVI / HDMI receivers. It is not possible to passively adapt an HDMI transmitter or DVI transmitter to work with a DisplayPort receiver.
3. DisplayPort can be used to daisy chain multiple displays from the same source. No other format can do this.
4. DisplayPort natively supports up to 16 bits per sRGB colour channels (48 bits per pixel). Single link DVI supports only 8 bits per sRGB channel (24 bits per pixel) and HDMI 16 bits only with subsampling. Dual Link DVI supports up to 16 bits per sRGB channel. This means that DisplayPort is equivalent to Dual-Link DVI for professional displays.