# Defined color not working in tcolorbox

I am using xcolor to define two custom colors and try to implement them in my tcolorbox boxes. MWE:

\documentclass{article}
\usepackage[dvipsnames]{xcolor}
\usepackage{tcolorbox}
\definecolor{myblue}{rgb}{3,78,170}
\definecolor{myred}{rgb}{255,243,212}
\begin{document}
\begin{tcolorbox}[colframe=myblue, colback=myred, toprule=1pt, bottomrule=0.5pt, leftrule=0pt, rightrule=0pt, arc=0pt]
TESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTE
TESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTEST
TESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTESTTEST
\end{tcolorbox}

\textcolor{myred}{Test?}

\end{document}


But there is no text visible. Also

• rgb only accepts values between 0 and 1. Try with RGB instead. – leandriis Jan 14 '20 at 19:36
• I swear I just copy and pasted my color definitions from another working document... But that was the answer. – Katjuscha Jan 14 '20 at 19:41
• @leandriis Can you convert your comment into a response? – AndréC Jan 14 '20 at 19:49
• @AndréC: done. Tanks for reminding me. – leandriis Jan 14 '20 at 20:24
• Not duplicated, but similar problem: tex.stackexchange.com/q/304009/1952 – Ignasi Jan 15 '20 at 8:33

According the the xcolor documentation,
the rgb color model only accepts values between 0 and 1. The RGB color model on the other hand accepts integers between 0 and 255, so swithing your definitions to
\definecolor{myblue}{RGB}{3,78,170}