I would like my planet to be inhabitable by many species and humanoids. It has a cold climate than earth. I'd like the sky to be an yellowish pale orange. Would that change the color of grass or leaves as an overview?
Color is Surprisingly Unimportant
The plants we see today are green which is actually kind of weird because sunlight according to black body radiation should have a peak wavelength of roughly 500nm (https://hypertextbook.com/facts/2002/TahirAhmed.shtml) which is right on the edge between cyan and green, but the atmosphere filters out shorter wavelength light putting the peak more at a greenish yellow. That means plants in real life are reflecting the peak wavelength of light! Stranger still there are archaea (a very ancient, but still extant form of microorganism) with a very simple form of photosynthesis that uses purple pigment! This not only absorbs the peak band of energy, but is also likely an older form of photosynthesis! At the end of the day, the visible light specturm is only a tiny part of the overall specturm of light and the color of plants depends more on what works now than what's optimal. Leaves can also have pigments completly unrelated to photosynthesis. For example, where I live there are blue spruces which get their blue hue from the protective wax that covers their needles. Some trees have purple leaves (either year round or during autumn) from anthrocyanine which can act as a sort of sunscreen (ironic isn't it?) in very sunny environments or a deterent from pests. Nature plays it fast and loose when it comes to foliage and so can you!
They will absorb the wavelengths that are the most steady and reliable
The green color of Earth plants seems strange at first, since it means they reflect the green wavelengths of light, which are the strongest wavelengths that reach the Earth's surface. For some time, it was believed that this was basically an accident; that plants which could absorb the green wavelengths would technically be superior but chlorophyll was "good enough".
However, it turns out that the evolutionary pressures on photosynthetic organisms are more nuanced than simply absorbing as much energy as possible. The issue is that while green wavelengths are abundant, they also fluctuate significantly over the course of a day, and the amount of green light hitting a plant will change a lot depending on whether it is in direct sunlight or shade.
Absorbing too much energy can be dangerous for an organism that is not prepared to manage it, resulting in free radicals and damaged tissues, and evolving to block out high-energy wavelengths will prevent it from absorbing them when they are weaker. Switching from one "mode" to another can be costly, so what an organism wants is not the strongest light, but the most reliable wavelengths, so that it gets a steady and predictable influx of energy that it can evolve to absorb efficiently.
On Earth, red light is scattered through the atmosphere, so it will hit a plant whether it is in direct sunlight or shade. And because the sky is blue, blue light will hit the plant regardless of where the sun is in the sky. So Earth plants evolved to absorb red and blue light, while reflecting the stronger but more volatile green light.
This same effect also predicts the color of other photosynthetic organisms on Earth, such as aquatic red and purple bacteria which tend to live at depths where blue or green light provide the most reliable source of energy.
So back to your question: since the sky is yellow (regardless of the position of the sun), plants will probably benefit most from absorbing yellow light, and they will also benefit from red for the same reason as on Earth. This means they will probably be blue.
the answer by @indigofenix is wonderful and i think fulfilled the needed answer. I'm only want to add this video by artifexian. this video talk about the correlation between the color of the sky and the color of the leaves of plants. i think this video could help you a lot in this topic.