he/you forgot about alpha argument..
https://wiki.multitheftauto.com/wiki/DxDrawImage
local defR = 255
local defG = 255
local defB = 255
function changeBackground(r,g,b)
defR, defG, defB = r, g, b
end
addEventHandler("onClientPlayerDamage", getLocalPlayer(), function()
changeBackground(255, 0, 0)
setTimer(changeBackground, 1000, 1, 255, 255, 255)
end)
addEventHandler("onClientRender", getRootElement(), function()
dxDrawImage(37, 450.5, 147.5, 130,"asd.png",0.0,0.0,0.0,tocolor(255, defR, defG, defB),false)
end)