In the best potential phrases, it may be proven that “As” is:

43 – since every quantity is merely ten higher than the atomic variety of the corresponding Periodic Table ingredient:

He → Helium (atomic quantity 2) + 10 = 12
Si → Silicon (atomic quantity 14) + 10 = 24
Fe → Iron (atomic quantity 26) + 10 = 36
so As → Arsenic (atomic quantity 33) + 10 = 43

The colors of the symbols are irrelevant – a ‘pink herring’, if you want…

However, additionally it is potential to include the image color and to provide a price for “As” of:

46 (which was the OP’s precise intent, as talked about in feedback beneath). The formulation behind this makes use of three items of knowledge:

– the variety of letters within the title of the color,
– the variety of letters within the full English title of the chemical ingredient, and
– the ingredient’s atomic quantity.

All we have to do is add the three collectively…

Blue He → BLUE (4 letters) + HELIUM (6 letters) + atomic quantity 2 = 12
Red Si → RED (3 letters) + SILICON (7 letters) + atomic quantity 14 = 24
Purple Fe → PURPLE (6 letters) + IRON (4 letters) + atomic quantity 26 = 36
so Yellow As → YELLOW (6 letters) + ARSENIC (7 letters) + atomic quantity 33 = 46

It is unlucky for the OP that for the primary three components chosen, the variety of letters of their color and full title all add as much as 10!