Why profit factor have different color?

These optimization colors have a meaning in all factors, the darkest the green the healthier the result, light green and yellow are medium and red are the worst.

healthier and worst in terms of what? is it drawdown?

Among the other factors that you used for your optimization, if you check the other factors in your photo above, you will see that 1.37 1.36 an 1.35 have better other factors than 1.34 ans 1.33.

obviously hahahaha. But Sometimes I got result that have lower profit factor but with darker green and I don't know why it appears like that.

They can be other factors, except the ones you are optimizing, as the drawdown you mentioned earlier, generally the darker the green the better it is.