How to change the background color of a latex poster in this particular template?

I am a beginner at using LaTex. I want to make a research poster with the below restrictions:

• at least 1000px for the width
• at least 600px for the height
• max 3MB
• No transparent background

I have found a template, here it is, and here is its code: https://www.overleaf.com/latex/templates/stockholm-university-poster-template/xsrhnggqmcsx

documentclass[20pt,,margin=1in,innermargin=-4.5in,blockverticalspace=-0.25in]{tikzposter}
geometry{paperwidth=42in,paperheight=32.5in}
usepackage[utf8]{inputenc}
usepackage{amsmath}
usepackage{amsfonts}
usepackage{amsthm}
usepackage{amssymb}
usepackage{mathrsfs}
usepackage{graphicx}
usepackage{adjustbox}
usepackage{enumitem}
usepackage[backend=biber,style=numeric]{biblatex}
usepackage{SUtheme}

usepackage{mwe} % for placeholder images

addbibresource{refs.bib}

% set theme parameters
tikzposterlatexaffectionproofoff
usetheme{SUTheme}
usecolorstyle{SUStyle}
usetitlestyle{Filled}

usepackage[scaled]{helvet}
renewcommandfamilydefault{sfdefault} 
usepackage[T1]{fontenc}


title{Stockholm University Scientific Computing Poster Template}
author{Qi Dang}
institute{Stockholm University}
titlegraphic{includegraphics[width=0.06textwidth]{su_logo/SU_logo_NEG_ENGELSK.eps}}

% begin document
begin{document}

but, I need to change the colors. Instead of the blue highlights of the titles, I need them to be yellow and to make the background color sort of a navy color like this one

Also I need to move the Uni. logo from above to the bottom like this one from MIT.