I started off by getting a Lee Filter Swatch book (the Designer edition), with is a neat little deal that has about 200 or so different color swatches of gel material, with each one measuring about 1.25" x 3.25", so big enough to cut out 2 or 3 circles and place over the front glass of the light. These are also made by Roscolux and Cinegel. Here is an example, but look around, as you can often find them for less:
https://www.cinemagadgets.com/leeswatchbook.html
These are neat because you can play with the different amounts of filtration, so just a little, or a bit more color correction, plus many of them also have swatches of diffusion material that is good for softening the light, so making a light floodier.
If you can remove the bezel, you just cut to size, place under the glass, and put the bezel back on. If the bezel doesn't come off, simply cut to size and attach with a tiny piece of double sided tape in the middle.
Personally, I've found that almost all my lights look better with either a minus 1/4 green or minus 1/2 green filter (which are magenta filters), so ended up purchasing a 21" x 24" square and just cut out what I need because remember, you'll only get 2 or 3 circles from each swatch in the swatch book, and most of the colors you won't be using. By the way, you can stack filters, so stacking two -1/4 green filters is equal to one -1/2 green filter. And do remember, adding any filter will decrease light output, but with most of today's high powered lights that is rarely a problem.
https://www.cinemagadgets.com/31-lee-s249.html
https://www.cinemagadgets.com/31-lee-s248.htm
One other thing. Lee has a new filter material specifically made for LEDs. I believe it's the Zircon series, and I think it's more heat resistant (but also a bit more expensive). I've never tried it, but I've never had any problems with the regular filter material on my 2300 lumen lights, but if interested, you can read all about it on the Lee Filter website:
https://www.leefilters.com/lighting/zircon.html
