HDMI 1.3 means it can do what they call "deep color" - of course your TV set will need to be newer and of the higher end variety to be able to make use of that. Deep color just means that the number of colors is increased to some huge amount that are capable of being displayed... It can also take in or send out HD audio formats from blu-ray discs... though depending on the make / model of the receiver it may not be able to decode these formats even though the hdmi can pass them through.

I have seen both on the deep color thing and can not tell the difference, though I am sure that there are those who can.

.

Quoting Ascended_Saiyan:

Quote:
Also, I don't know of any Deep Color commercially available content that exists (except Life with Playstation on the PS3), therefore you wouldn't see a difference, now.  You can create your own by using AVCHD camcorders (they support Deep Color).

You may not have a TV or content that supports Deep Color at the moment, but how long do you want to keep this receiver.  If you want to keep this A/V receiver for a long time, it might be worth it to future proof your A/V receiver.  That way it's just a plug and play thing with your future TV and content purchase (or your own home movies shot with a AVCHD camcorder that you may buy in the future).

If future proofing your purchases is not something you usually do, I would suggest the cheaper A/V receiver.

Well there are two Blu Ray movies that support deep color.

As to the original question. All good receivers like the Yamaha 663, the onkyo 606, Denon 1909 and the even the Sony STR-DG 820 they all support Deep colour throughput.. Also you would need a TV Set that can actually take advantage of that.
I don't know what player you wanna buy but I would go for the Onkyo

also see this site for HDMI 1.3 info

http://www.hdtvsupply.com/hd13rade.html

The latest HDMI Version 1.3 upgrade gives you:

    * Higher speed: HDMI 1.3 increases its single-link bandwidth to 340 MHz (10.2 Gbps) to support the demands of future HD display devices, such as higher resolutions, Deep Color and high frame rates. In addition, built into the HDMI 1.3 specification is the technical foundation that will let future versions of HDMI reach significantly higher speeds.
    * Deep Color: HDMI 1.3 supports 10-bit, 12-bit and 16-bit (RGB or YCbCr) color depths, up from the 8-bit depths in previous versions of the HDMI specification, for stunning rendering of over one billion colors in unprecedented detail.
    * Broader color space: HDMI 1.3 adds support for “x.v.Color™” (which is the consumer name describing the IEC 61966-2-4 xvYCC color standard), which removes current color space limitations and enables the display of any color viewable by the human eye.
    * New mini connector: With small portable devices such as HD camcorders and still cameras demanding seamless connectivity to HDTVs, HDMI 1.3 offers a new, smaller form factor connector option.
    * Lip Sync: Because consumer electronics devices are using increasingly complex digital signal processing to enhance the clarity and detail of the content, synchronization of video and audio in user devices has become a greater challenge and could potentially require complex end-user adjustments. HDMI 1.3 incorporates automatic audio synching capabilities that allows devices to perform this synchronization automatically with total accuracy.
    * New HD lossless audio formats: In addition to HDMI’s current ability to support high-bandwidth uncompressed digital audio and all currently-available compressed formats (such as Dolby® Digital and DTS®), HDMI 1.3 adds additional support for new lossless compressed digital audio formats Dolby TrueHD and DTS-HD Master Audio™.

These HDMI 1.3 products are compatible with HDTV's with a 120 Hz frame rate and Blu-ray, HD-DVD DVD players etc. with a 24 Hz frame rate.