Rare Grace's Warbler in San Isabel Nat Forest

While birding in the San Isabel National Forest in Custer County last week I saw a warbler with a bright yellow throat and breast. It was very high in a ponderosa pine tree and I was only able to catch a few glimpses of it as it foraged towards the inside of the branches. I thought it was a Grace's Warbler but with such brief glimpses I didn't get all the field marks and I wasn't familiar with its song to use to confirm the id. I don't have a tape or other device with songs since I don't use tapes to attract birds due to the risk of disrupting their behavior.
When I got home I listened to the song of the Grace's Warbler on the internet and it sounded familiar, but since I didn't get home for several hours I wasn't positive that this was the song I had heard (I just can't keep a song from an unfamiliar bird in my head for too long).
I wasn't able to get back out there to look for the bird again until yesterday but I didn't see it. Though I didn't realize it at the time (I didn't listen to the song before I left), I had heard it singing which I realized when I got home and listened to the song on the internet. So today I went prepared--I listended to the song before I left home and whistled it to myself to keep it fresh in my memory. A little while after I got there I thought I heard the song so I whistled my not-so-good rendition of the song. A warbler flew into a pine tree not far away and it was the Grace's Warbler. It foraged and sang for another 15 or so minutes until some strong winds came up. Most of time it was high in a pine tree which is the habit with these warblers but I was able to see it with my binoculars several times and got a few pics.

The bottom pic didn't come out very good because of the overcast sky behind it that just sucked up most of the color. When I took the other two pics the warbler was about 50-60 feet up in a tree and almost 100 feet away but the top pic came out fairly well.
SeEtta