Let's invite an expert's opinion
Dr William Stiles of Aberystwyth University wrote the following (emphasis is mine):
Light is an essential component of plant development and is a key driver of plant physiology and morphology. Light is crucial for photosynthesis, the chemical reaction that fixes CO2 for the purposes of food production, but it also acts as an environmental prompt, informing plants about the world in which they exist. Plants detect information from incoming light using sophisticated multi-functional sensory proteins called photoreceptors. Plants possess at least five classes of photoreceptor: phytochromes, cryptochromes, phototropins, Flavin-binding F-box proteins, and UVR8. Actual signalling pathways, and the interaction between different receptors, are complex, but in essence phytochromes perceive red and far-red light, cryptochromes perceive blue and UV-A light, phototropins and Flavin-binding F-box proteins blue light, and UVR8 perceives UV-B light.
...
Light from within the visible spectrum drives photosynthesis, particularly light from within blue and red wavelength ranges, but the potential for photosynthesis will be governed by the amount of energy available in the form of photons that a plant can absorb. Light intensity, and its potential for driving photosynthesis, is referred to as the photosynthetic photon flux density (PPFD). The higher the PPFD, the higher the potential for photosynthesis. Plants absorb light energy via the light-absorbing pigment chlorophyll. Chlorophyll appears green as it absorbs all visible light except green wavelengths, which are reflected. Chlorophyll A and B absorb red and blue light strongly, and as such these wavebands have been considered the only portion of light that truly matters for plant production. However, increasingly it is recognized that plants make use of all available light to at least some degree, including green light, and that presence (or absence) of different wavebands influences plant development.
...
Each of the wavebands of the light spectrum, and their relative proportion in the available light, will trigger a response in the plant. The different wavebands are:
Red light (600-700 nm) – light from the red wavelengths is the main driver of vegetative growth. This means more leaves and more biomass. But growing in the absence of other spectra may result in a phenomena referred to as red-light syndrome, where leaf photosynthesis can become impaired. Without the presence of blue light, the form or morphology of plant tissues may also result in unfavourable growth profiles, where plants become stretched and tall, with thin leaves, which is a typically unfavourable growth profile. It may also mean plants cannot utilise all available light energy, leading to overall inefficiency. Overall, red is the most important wavelength for plant growth and development, but not in isolation.
Blue light (400-500 nm) – light from the blue portion of the spectrum has a large effect on plant morphology. It can increase the ratio of root to shoot in plant development, promoting root growth and plant compactness, which has certain implications depending on production goals. Blue light also promotes more stomatal opening, which means more stomatal conductance and gas exchange. This is typically considered favourable from a plant health perspective but may result in greater humidity potential, which is a consideration for controlled environments. Blue light is absorbed readily by plant photoreceptors, and is an important factor in plant environmental perception. For instance, increasing the percentage of blue light will convince plants that there is more available light overall, which will change plant behaviour.
Green light (500-600 nm) – green light is weakly absorbed compared to red and blue wavelengths, but is increasingly recognised as important for overall photosynthesis potential. Green light is reflected and scattered within leaves and the canopy, which increases the potential for total absorption. Green is particularly important in dense-growing scenarios where there is a large amount of shading, as it drives photosynthesis in lower or shaded leaves. Green light also affects morphology via the green to blue light ratio. This acts as a signal to indicate shade conditions, informing the plant and leaf of its position in the canopy, initiating growth behaviour associated with shade avoidance. This can include extra growth or stretching of the internode and leaf length, and the angle of the leaves may also change to capture more incidental rather than direct light.
Far-red (700-850 nm) – this portion of light is referred to as super-visual, as the majority of this waveband is outside the visible portion of the spectrum. Far-red is not considered conventionally photosynthetically active and it only weakly drives photosynthesis, but adding far-red will change how plants grow as this light is absorbed by phytochrome photoreceptors, which are involved in the regulation of leaf expansion, flowering, internode extension, and the partitioning of resources between organs. Far-red will also have the opposite effect to blue light on root to shoot ratio, resulting in higher shoot to root distribution. Yet, as with all elements of the light spectrum, there is a balance to be struck between a beneficial amount of far-red light and too much. Plants grown under high levels of far-red light will appear tall and stretched, with lower chlorophyll content resulting in yellowing of the leaves, which is perhaps unfavourable from a marketability perspective. In addition to direct effects, the ratio of red to far-red light is also an important mechanism for governing plant responses. Far-red penetrates the canopy more than red light, so plants receiving a higher amount of far-red relative to red will interpret this as a shading effect, and increase shade avoidance responses such as increased upwards growth.
UV spectrum (100-400 nm) – UV light is also outside of the PAR wavelengths, but this light will still affect plant development. Plant responses to UV-A light are similar to blue light. UV-B is higher energy and has its own photo receptor in plants, called UVR8. Adding UV-B to the spectrum will change the morphology in ways which are not considered essential for survival, but which may affect the potential for production. For instance, under UV-B light plant cuticles can grow thicker, making the plants generally more robust, and UV-B exposure will positively regulate stomatal development, but hypocotyl and petiole length may be shorter and rosette leaf expansion may be impaired. Secondary metabolite production is also higher under UV-B, which is typically a favourable response, particularly for production systems focussing on pharmaceutical production. UV-C is not believed to be directly perceived by plants, but it can be highly useful for the control of pests and disease in controlled environments.
Summary
Light across the so-called visible spectrum is used by plants — not just the red spectrum. Losing the red spectrum would have a detrimental affect on the plants, and therefore any animals dependent on the plants. But would your world kill the plants?
NO
Blocking and/or scattering enough light to let the sun appear blue to human eyes does not mean that no red light is striking the surface. There would still be sufficient red light to promote plant growth and, obviously, plenty of the other spectra of light to positively affects plants.
As a quick aside... if you did block all the red spectra light, that means that NOTHING on your planet would appear red because there's no red light to reflect. Chalk that one up to the Law of Unintended Consequences, so it's good that some red spectra light is getting through.
However, and as a viable and interesting part of your story, plants would suffer. Or, perhaps said better another way, they would not be as prolific under the conditions you propose as they would be on Earth. What that means is that they'll need to adapt. Human history and science has demonstrated that biology is really, really, good at adapting. It will take some time (if not helped by intentional human effort), but I don't see a reason why the plants wouldn't be adequate in the beginning and fine over time. (OK, thousands if not millions of years worth of time... but still....)
What about the animals? Tell me about UV...
I don't think your animals have any problems at all. The presence of red-spectrum light doesn't mitigate the effects of UV light. It could be true that if you require a brighter star in order to have the same luminosity on the surface of your world as we do here on Earth, that would up the UV. But that also ups the heat and a lot of other things (like upping the solar wind...). That means plant and animal life are threatened for reasons that have little to do with the question you asked.
If, indeed, the sun is "similar to our own" in that the star's output is similar to Sol's output, then you have no problems at all. The world would be (frankly, imperceptibly) dimmer and the star would look blue, but that's it. Nothing would die.
Now, a particulate count high enough to achieve what you're proposing, depending on what those particles are... that could kill everything. Or at least give everything with lungs and sinuses the worst case of chronic hay fever ever heard of. But I'll leave that issue up to you.
