diff --git a/beamerThemeOtagoPlain/beamercolorthemeOtagoPlain.sty b/beamerThemeOtagoPlain/beamercolorthemeOtagoPlain.sty
index 89d6c22..25d5e0d 100644
--- a/beamerThemeOtagoPlain/beamercolorthemeOtagoPlain.sty
+++ b/beamerThemeOtagoPlain/beamercolorthemeOtagoPlain.sty
@@ -22,12 +22,12 @@
 % https://web.archive.org/web/20230207091139/https://www.otago.ac.nz/administration/service_divisions/external-engagement/otago017269.html#colourvalues
 %
 % Blue - RGB: 0, 80, 143; CMYK: 100, 60, 0, 25; HTML: #00508F
-\definecolor{old OU blue}{rgb/cmyk}{0,0.314,0.56/1,0.6,0,0.25/00508F}
+\definecolor{old OU blue}{rgb/cmyk/HTML}{0,0.314,0.56/1,0.6,0,0.25/00508F}
 % Red - RGB: 198, 53, 29; CMYK: 0, 95, 90, 0; HTML: #CE2227
 % (no longer an official colour)
-\definecolor{OU red}{rgb/cmyk}{0.776,0.208,0.114/0,0.95,0.9,0}
+\definecolor{OU red}{rgb/cmyk/HTML}{0.776,0.208,0.114/0,0.95,0.9,0/CE2227}
 % Gold - RGB: 250, 198, 0; CMYK: 0, 25, 100, 0; HTML: #F9C013
-\definecolor{old OU gold}{rgb/cmyk}{0.98,0.776,0/0,0.25,1,0}
+\definecolor{old OU gold}{rgb/cmyk/HTML}{0.98,0.776,0/0,0.25,1,0/F9C013}
 %
 % New colours (from 2024-05-01)
 % https://www.otago.ac.nz/marketing-services/resources/university-of-otago-brand-guide#k%C4%81-tae---colours
@@ -82,7 +82,8 @@
 %
 % Other miscellaneous colours.
 %
-\definecolor{lavender}{rgb/cmyk}{0/0.451,0.333,0.4,0.48,0.61,0.35}  % RGB 115, 85, 102
+% Lavender (probably more puce TBH) - RGB: 115, 85, 102; CMYK 0, 26, 11, 55; HTML: #735566
+\definecolor{lavender}{rgb/cmyk}{0.451,0.333,0.4/0,0.26,0.11,0.55}
 \colorlet{dull green}{green!40!black}
 
 \setbeamercolor{lavender text}{fg=lavender}