try this
function getHealthColor()
local health = getElementHealth(localPlayer)
if (health) then
local g = (255/1000) * health
local r = 255 - g
local b = 0
return r, g, b
else
return 0, 255, 0
end
end
---------------------------------------------
local image = "textures/carState.png"
local csr, csg, csb = getHealthColor()
dxDrawImage(screenWidth - 30, screenHeight - 125, 24, 24, image, 0, 0, 0, tocolor(csr, csg, csb , 255), true)