Some Thesaurus words for "radiant" - beaming, blissful, brilliant, cheery, delighted, effulgent, gleaming, glorious, glowing, incandescent, joyful, lambent, lucent, lustrous, radiating, rapturous, resplendent, shining, sparkling, sunny.
In this photo where nature obviously lost, my artistic side was sparked with energy. I was delighted to see this vibrant color and it caught my eye while driving by. I actually backed up the car to see exactly what was glowing in the sunlight. Yes, you can imagine my surprise when I saw what the road crew had done quite artistically I might add :)