So can i mount it on a heat sink?

It depends. There's no one-size-fits-all solution for SMD LED heatsinking.

The datasheet may give you some recommendations. Most likely, you'll need an array of vias under the package to transfer heat to the backside of the PCB where you can attach a heatsink.

 

So can i mount it on a heat sink?

The ones you picked out are surface mounted LEDs that are soldered onto a circuit board. Not only that they are also requiring up to 1A MAX, typically 350mA at very low voltages ~2.5 - 3.5V. 3.5V x 350mA = 1.225W x 3 colors is 3.675W of heat to be dealt with? The PDF shows luminous flux degradation above 25 degrees C. So you have to surface mount them on circuit board, provide them with a significant current at 3 different very low voltages and keep them cool? How are you going to do this?

 

The ones you picked out are surface mounted LEDs that are soldered onto a circuit board. Not only that they are also requiring up to 1A MAX, typically 350mA at very low voltages ~2.5 - 3.5V. 3.5V x 350mA = 1.225W x 3 colors is 3.675W of heat to be dealt with? The PDF shows luminous flux degradation above 25 degrees C. So you have to surface mount them on circuit board, provide them with a significant current at 3 different very low voltages and keep them cool? How are you going to do this?

I can’t mount the LEDs on a circuit board, I have to fit the LEDs into a beer bottle. Do the ones you recommend have these problems?

 

I can’t mount the LEDs on a circuit board, I have to fit the LEDs into a beer bottle. Do the ones you recommend have these problems?

All high power LEDs will require heatsinking unless they're operated at low power.

It would be helpful if you showed your proposed mounting and gave your area constraints.

 

General information about LEDs
http://www.gizmology.net/LEDs.htm

5mm RGB datasheet
https://www.sparkfun.com/datasheets/Components/YSL-R596CR3G4B5C-C10.pdf

They also come in 3mm diameter size and possibly larger

General selection on Amazon including some "pre-wired" with pigtails
https://www.amazon.com/s?k=rgb+leds...Z&sprefix=rgb+leds,aps,155&ref=nb_sb_ss_i_3_8

These are the 20mA variety.

 

General information about LEDs
http://www.gizmology.net/LEDs.htm

5mm RGB datasheet
https://www.sparkfun.com/datasheets/Components/YSL-R596CR3G4B5C-C10.pdf

They also come in 3mm diameter size and possibly larger

General selection on Amazon including some "pre-wired" with pigtails
https://www.amazon.com/s?k=rgb+leds+5mm&crid=3HK4QO4P18JQZ&sprefix=rgb+leds,aps,155&ref=nb_sb_ss_i_3_8

These are the 20mA variety.

Will they be as less bright?

 

Will they be as less bright?

Read the datasheets...

 

Will they be as less bright?

Yes; LED brightness is dependent on forward current. Whether it's too dim depends on your application.

 

I can’t mount the LEDs on a circuit board, I have to fit the LEDs into a beer bottle. Do the ones you recommend have these problems?

First, you could mount the LEDs on a circuit board. The LEDs are a tad less than 0.2” square; the bottle neck is a tad more than 1.0” in diameter. So if the smallest dimension of your PCB is a little less that 1.0” (say 0.9”) and it’s length could be longer... it would fit in the beer bottle.

Secondly, about placing them in s beer bottle... The bottle will trap heat while making it more difficult to cool the LEDs. I’d checkout the suggestions made by @SamR