Tikz arrow color
\documentclass[tikz]{standalone}
\usetikzlibrary{arrows.meta}
\begin{document}
\begin{tikzpicture}[my triangle/.style={-{Triangle[width=\the\dimexpr1.8\pgflinewidth,length=\the\dimexpr0.8\pgflinewidth]}}]
\draw[line width=16pt,my triangle,
postaction={draw,orange,line width=14pt,my triangle,shorten >=1pt,shorten <=1pt}](0,0) -- (1,0);
\end{tikzpicture}
\end{document}
Why not using the shapes.arrow
library?
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.arrows, fadings}
\begin{document}
\begin{tikzpicture}
[every node/.append style={
draw=black,
line width=4pt,
single arrow}
]
\node [
fill=orange,
minimum height=10cm,
minimum width=8cm
] {};
\node at (0,8) [
right color=purple,
left color=cyan,
single arrow head extend=0.4cm,
single arrow tip angle=70,
single arrow head indent=0.7cm,
minimum height=12cm,
minimum width=8cm,
shading angle=-45,
rotate=45
] {};
\end{tikzpicture}
\end{document}