How to get this effect?

In Photoshop, try running Gaussian Blur filter over it with a generous radius, then Edit>Fade>Overlay... after that, you could also then mess with Curves and/or Saturation to get the final result you want.

that actually looks like an hdri photo to me, which can bring out some loverly strong colours, but sure you could fake that kind of saturation

try duplicating the layer then, for the new layer

set blending options to soft light.
Image -> Adjust -> Hue / Desaturate. Set Desaturate to -70
Image -> Adjust -> Brightness & Contrast set both to +10
Filter -> Blur -> Gaussian Blur - Set to 7.0 .

Flatten the image and play with levels settings

speakerwizard said:

that actually looks like an hdri photo to me

Click to expand...

Good call, that's what it looks like it to me.