Hi Aftab - Welcome to PhotoshopGurus.com.
First, a bit of terminology. Among photographers, the word, "tones" or "tonality" means the distribution of brightness throughout the image. It is entirely separate from the "color" (ie, hue and saturation) aspects of an image. To think of tones for a color image, just imagine it was converted to gray scale (ie, a "black and white" photo), and then think about how deep are the blacks and shadow areas, how bright are the highlights, how much mid-range contrast is there, etc. etc. Think of what the histogram for the B&W version would look like. In short, your phrase, "color tones" maybe should have been better expressed as "colors and tones"
I brought the definition of "tones" up immediately because it is critically important to producing the pix you posted. It is the first thing that caught my attention. Here are histograms for the two images.
Note that there are no black pixels whatsoever, and very, very few deep shadow pixels in either image. This is one of the major factors that contribute to the low contrast look in these images. There are some subtleties to this, but a very easy way to get close is to put a "Levels" adjustment layer above your image, and then move the slider circled in red from the extreme left position to the position shown (obviously, adjust to the demands of your image and your own taste).
There are two other items that are critical to giving these two images their characteristic look, and these have absolutely nothing to do with Photoshop: The lighting and the lens used.
The simplest is the lens. In both these pictures, the background is thrown way out of focus and shows only extremely softened versions of the items that are really there. This is done by using a long focal length lens, and opening it up to at least f/4, and probably more like f/2.8 or even f/2. This softening contributes tremendously to the overall look.
The lighting is of equal importance. First, notice that the light in the background is of a completely different color than the lighting in the foreground. In forest settings, whites tend to take on a yellow or greenish cast, but there are only traces of this remaining in the white dresses of the girls. This immediately tells me that the photographer added some extra light to the subjects. Next, notice that there are hardly any shadows on the subjects -- they are lit with a very soft light, not a simple, harsh, on-camera flash. He could have done this in a number of ways. From the annular catchlights (ie, reflections of the flash) in the eyes of the girl, it looks like he might have used a light modifier called a beauty dish, but he could have gotten a similar effect with a photographic umbrella, softbox or octobox (Google these terms), or even just bouncing a hot-show flash up into a big reflector just above the camera.
If even one of the aspects mentioned above (eg, color balance, missing blacks, long lens used wide open, & a nice big, soft source of light) is missing, the result will be substantially different.
HTH,
Tom M
