TL;DR
The Singapore flag could have been blue.1 It was one of several proposed designs that had been put forward by founding father Deputy Prime Minister Toh Chin Chye (10 December 1921 - 3 February 2012) and his committee.2 Eventually, another design – red and white with five stars and a crescent – was picked. Toh, who was the People’s Action Party’s (PAP) founding chairman, had been given the task of developing Singapore’s official symbols to reflect the values and identity of the newly-formed self-governing state.
Apart from the flag, Dr Toh also contributed to the design of the state crest3 and worked on the national anthem with composer Zubir Said4
Notes
1 https://www.straitstimes.com/singapore/flying-high
2 https://www.nlb.gov.sg/main/article-detail?cmsuuid=66bb01bf-8643-4d4b-b77b-8dd01a185e3b
3 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
4 https://www.nlb.gov.sg/main/article-detail?cmsuuid=566487d5-7862-4dc7-8f8b-162356ec2b5c
5 https://www.pmo.gov.sg/newsroom/prime-minister-lee-hsien-loongs-condolence-letter-demise-dr-toh-chin-chye
6 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
7 https://www.asiaone.com/News/Latest%2BNews/Singapore/Story/A1Story20120204-325912.html
8 https://www.asiaone.com/News/Latest%2BNews/Singapore/Story/A1Story20120204-325912.html
9 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
10 https://www.pmo.gov.sg/newsroom/prime-minister-lee-hsien-loongs-condolence-letter-demise-dr-toh-chin-chye
11 https://www.nlb.gov.sg/main/article-detail?cmsuuid=1b1f20c7-d8b6-4ee2-a0bc-90eaf7828da7
12https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
13Kevin Tan & Lam Peng Er (2018). Lee’s Lieutenants: Singapore’s Old Guards. Singapore: Straits Times Press, p. 46
13 https://www.nlb.gov.sg/main/article-detail?cmsuuid=1b1f20c7-d8b6-4ee2-a0bc-90eaf7828da7
14 https://www.nlb.gov.sg/main/article-detail?cmsuuid=1b1f20c7-d8b6-4ee2-a0bc-90eaf7828da7
15 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
16 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
17 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
18 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
19 https://www.nlb.gov.sg/main/article-detail?cmsuuid=4452dd93-d862-4310-bf0e-4f6ff52812a8; https://www.asiaone.com/singapore/spore-founding-fathers-dr-toh-chin-chye-ensured-spore-flag-was-all-inclusive
20 https://www.nlb.gov.sg/main/article-detail?cmsuuid=566487d5-7862-4dc7-8f8b-162356ec2b5c
21 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
22 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
23 https://www.nlb.gov.sg/main/article-detail?cmsuuid=a733f1d4-f0e8-47d6-8f1e-dadaaea396d4
24 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
25 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
26 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
27 https://www.nas.gov.sg/archivesonline/audiovisual_records/record-details/51f06bc5-1164-11e3-83d5-0050568939ad
2 https://www.nlb.gov.sg/main/article-detail?cmsuuid=66bb01bf-8643-4d4b-b77b-8dd01a185e3b
3 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
4 https://www.nlb.gov.sg/main/article-detail?cmsuuid=566487d5-7862-4dc7-8f8b-162356ec2b5c
5 https://www.pmo.gov.sg/newsroom/prime-minister-lee-hsien-loongs-condolence-letter-demise-dr-toh-chin-chye
6 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
7 https://www.asiaone.com/News/Latest%2BNews/Singapore/Story/A1Story20120204-325912.html
8 https://www.asiaone.com/News/Latest%2BNews/Singapore/Story/A1Story20120204-325912.html
9 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
10 https://www.pmo.gov.sg/newsroom/prime-minister-lee-hsien-loongs-condolence-letter-demise-dr-toh-chin-chye
11 https://www.nlb.gov.sg/main/article-detail?cmsuuid=1b1f20c7-d8b6-4ee2-a0bc-90eaf7828da7
12https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
13Kevin Tan & Lam Peng Er (2018). Lee’s Lieutenants: Singapore’s Old Guards. Singapore: Straits Times Press, p. 46
13 https://www.nlb.gov.sg/main/article-detail?cmsuuid=1b1f20c7-d8b6-4ee2-a0bc-90eaf7828da7
14 https://www.nlb.gov.sg/main/article-detail?cmsuuid=1b1f20c7-d8b6-4ee2-a0bc-90eaf7828da7
15 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
16 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
17 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
18 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
19 https://www.nlb.gov.sg/main/article-detail?cmsuuid=4452dd93-d862-4310-bf0e-4f6ff52812a8; https://www.asiaone.com/singapore/spore-founding-fathers-dr-toh-chin-chye-ensured-spore-flag-was-all-inclusive
20 https://www.nlb.gov.sg/main/article-detail?cmsuuid=566487d5-7862-4dc7-8f8b-162356ec2b5c
21 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
22 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
23 https://www.nlb.gov.sg/main/article-detail?cmsuuid=a733f1d4-f0e8-47d6-8f1e-dadaaea396d4
24 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
25 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
26 https://www.nlb.gov.sg/main/article-detail?cmsuuid=8a68761c-5b59-4758-a2ce-0793a8cddfb1
27 https://www.nas.gov.sg/archivesonline/audiovisual_records/record-details/51f06bc5-1164-11e3-83d5-0050568939ad










