Appearance of sun at geologic past After origin of Earth ( 4.54 billion years ago ) to today; what are the changes  through-which the sun undergone with time? , ( if seen from Earth. )

I'm doing some palaeobiology-landscape rendering; so I'm thinking if I want to add the sun in such pictures; should I draw it just like present day? Or the look/ appearance (colour, size, flames, position, halo etc) varied in observable amount through the geologic time-scale(precambrian-cambrian-ordovician-silurian-devonian-carboniferous-permian-triassic-jurassic-cretaceous-palaeogene-neogene etc). (the timescale terms provided just to hint the answerer the level of details may NOT to go )

Update: Here I attach a  small version of geologic time table to indicate time ranges. 

 

from here . 

To see the entire chart; see international commission of stratigraphy charts
I'm doing some palaeobiology-landscape rendering; so I'm thinking if I want to add the sun in such pictures; should I draw it just like present day ?


Although the Sun was less luminous 4.5 billion years ago (about 70% of it's current luminosity, it is thought), and while this would affect it's color, making it perhaps a little more orange than yellow, the effect is small.

The Sun is still going to be a blazing near-white object in the sky of roughly the same size.

Although there was probably a color shift to a slightly more orange tint, the composition of the Earth's atmosphere was radically different (see for example this page on Paleoclimatology) and this would have had a much more significant effect on the appearance of the Sun (and the lighting of the landscape) than any minor change in the Sun's appearance.

There are some issues relating to the development of life and this change in the Sun's luminosity (like the Faint Young Sun Problem) but these won't make much difference to your rendering, I think, compared to the atmospheric and climate issues.

However the climate changes are not fully understood and it's rather speculative to try and make specific claims about what the overall effect would have been on the illumination levels and color of light reaching the surface in these periods.